lm2596中文版
lm2596的资料
V V（min） V（max） % ２
η
效率
LM2596 开关电压调节器
符号 LM2596□—12 参量 （见注 14） 15V≤VIN≤40V， 0.2A≤ILOAD≤3A VIN=25V，ILOAD=3A 88 12.0 11.52/11.40 12.48/12.60 条件
SEPTEMBER， 2004
D1----5A/40V IN5825
图 1 标准测试电路
在开关调节器中，PCB 版面布局图非常重要，开关电流与环线电感密切相关，由这种环线电感所产生的暂态电 压往往会引起许多问题。要使这种感应最小、地线形成回路，图中所示的粗线部分在 PCB 板上要印制得宽一点，且 要尽可能地短。为了取得最好的效果，外接元器件要尽可能地靠近开关型集成电路，最好用地线屏蔽或单点接地。 最好使用磁屏蔽结构的电感器，如果所用电感是磁芯开放式的，那么，对它的位置必须格外小心。如果电感通量和 敏感的反馈线相交叉，则集成电路的地线及输出端的电容 COUT 的连线可能会引起一些问题。在输出可调的方案 中，必须特别注意反馈电阻及其相关导线的位置。在物理上，一方面电阻要靠近 IC，另一方面相关的连线要远离电 感，如果所用电感是磁芯开放式的，那么，这一点就显得更加重要。 ５
４
LM2596 开关电压调节器
测试电路及其布线方案（固定输出）
SEPTEMBER， 2004
注：反馈线要远离电感，电路中的粗线一定要短，最好用 地线屏蔽。 纹波滤波电路 CIN---470μF/50V COUT----220μF/25V L1---68μH，L38 D1----5A/40V IN5825
说明：标准字体对应的项目适合于 TJ=25℃时，带下划线的粗斜体字对应的项目适合于整个温度范围； 系统参量(4) 测试电路见图 1
LM2596中文资料
LM2596S-3.3, LM2596S-5.0,LM2596S-12， LM2596S-ADJ为TO-263封装（SMT）。
η
效率
VIN=12V，ILOAD=3A
73
LM2596□—5.0 （见注 14）
VOUT
输出电压
5.0 7V≤VIN≤40V， 0.2A≤ILOAD≤3A
η
效率
VIN=12V，ILOAD=3A
80
3.168/3.135 3.432/3.465
V V（min） V（max） %
4.800/4.750 5.200/5.250
2 30
A A(min) A(max) μA(max) mA mA(max)
IQ
静电流
见注 9
5 10
mA mA(max)
ISTBY
待机静电流
ON/OFF 脚=5V（OFF）（9）
80
μA
200/250
μA(max) ３
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LM2596 开关电压调节器 SEPTEMBER， 2004
ILOAD=500mA。 （见注 14）
361 符号
参量
cu 器件参数
.m Ib
反馈偏置电流
wwwfO
振荡器频率
条件
LM2596□—XX
典型值（2） 极限值（3）
单位
只适用于输出可调节的情况，VFB=1.3V
LM2596全中文资料
LM2596 开关电压调节器LM2596开关电压调节器是降压型电源管理单片集成电路，能够输出3A的驱动电流，同时具有很好的线性和负载调节特性。
固定输出版本有3.3V、5V、12V，可调版本可以输出小于37V的各种电压。
该器件内部集成频率补偿和固定频率发生器，开关频率为150KHz，与低频开关调节器相比较，可以使用更小规格的滤波元件。
由于该器件只需4个外接元件，可以使用通用的标准电感，这更优化了LM2596的使用，极大地简化了开关电源电路的设计。
其封装形式包括标准的5脚TO-220封装（DIP）和5脚TO-263表贴封装（SMD）。
该器件还有其他一些特点：在特定的输入电压和输出负载的条件下，输出电压的误差可以保证在±4%的范围内，振荡频率误差在±15%的范围内；可以用仅80μA的待机电流，实现外部断电；具有自我保护电路（一个两级降频限流保护和一个在异常情况下断电的过温完全保护电路）特点※ 3.3V、5V、12V的固定电压输出和可调电压输出※可调输出电压范围1.2V～37V±4%※输出线性好且负载可调节※输出电流可高达3A※输入电压可高达40V※采用150KHz的内部振荡频率，属于第二代开关电压调节器，功耗小、效率高※低功耗待机模式，I Q的典型值为80μA※TTL断电能力※具有过热保护和限流保护功能※封装形式：TO-220（T）和TO-263（S）※外围电路简单，仅需4个外接元件，且使用容易购买的标准电感应用领域※高效率降压调节器※单片开关电压调节器※正、负电压转换器典型应用（固定输出）LM2596□-5.0管脚图极限参数名称范围单位最大电源电压 45 V脚输入电压-0.3～25 V“反馈”脚电压 -0.3～25 V到地的输出电压（静态） -1 V功耗由内部限定 --储存温度 -65～150℃静电释放（人体放电1） 2000 V气流焊（60秒） 215 ℃ TO-263红外线焊接（10秒） 245 ℃ 焊接时的管脚温度TO-220 波峰焊/电烙铁焊接（10秒）260℃最高结温 150 ℃温度范围 -40～125℃工 作条 件电源电压 4.5～40 V注1：人体放电模式相当于一个100PF 的电容通过一个1.5K 的电阻向每个管脚放电。
lm2596中文资料
VIN=25V，VOUT =3V， ILOAD=3A
η
效率
VIN=25V，VOUT =15V，ILOAD=3A
电气特性（所有输出）
典型值（2） 极限值（3）
单位
12.0
88 1.230
73 90
11.52/11.40 12.48/12.60
V V（min） V（max） %
1.193/1.180 1.267/1.280
2000
V
气流焊（60 秒）
215
℃
焊接时的管脚
TO-263
温度
红外线焊接（10 秒）
245
℃
TO-220
波峰焊/电烙铁焊接（10 秒）
260
℃
最高结温
150
℃
工 作条 件
温度范围 电源电压
-40～125
℃
4.5～40
V
注 1：人体放电模式相当于一个 100PF 的电容通过一个 1.5K 的电阻向每个管脚放电。
电气特性
说明：标准字体对应的项目适合于 TJ=25℃时，带下划线的粗斜体字对应的项目适合于整个温度范围； 系统参量(4) 测试电路见图 1
符号
参量
条件
典型值（2）
极限值（3）
单位
LM2596□—3.3 （见注 14）
VOUT
输出电压
3.3 4.75V≤VIN≤40V，
0.2A≤ILOAD≤3A
η
效率
A(max)
50
μA(max)
2 30
mA mA(max)
5 10
mA mA(max)
80
μA
200/250
μA(max) ˏ
LM2596(开关电压调节器)中文版
η
效率
VIN=12V，ILOAD=3A
73
LM2596□—5.0 （见注 14）
VOUT
输出电压
5.0 7V≤VIN≤40V， 0.2A≤ILOAD≤3A
η
效率
VIN=12V，ILOAD=3A
80
3.168/3.135 3.432/3.465
V V（min） V（max） %
LM2596 开关电压调节器 SEPTEMBER， 2004
LM2596 开关电压调节器
LM2596 开关电压调节器是降压型电源管理单片集成电路，能够输出 3A 的驱动电流，同时具有很好的线性和 负载调节特性。固定输出版本有 3.3V、5V、12V， 可调版本可以输出小于 37V 的各种电压。
该器件内部集成频率补偿和固定频率发生器，开关频率为 150KHz，与低频开关调节器相比较，可以使用更小 规格的滤波元件。由于该器件只需 4 个外接元件，可以使用通用的标准电感，这更优化了 LM2596 的使用，极大地 简化了开关电源电路的设计。
其封装形式包括标准的 5 脚 TO-220 封装（DIP）和 5 脚 TO-263 表贴封装（SMD）。 该器件还有其他一些特点：在特定的输入电压和输出负载的条件下，输出电压的误差可以保证在±4%的范围 内，振荡频率误差在±15%的范围内；可以用仅 80μA 的待机电流， 实现外部断电；具有自我保护电路（一个两级 降频限流保护和一个在异常情况下断电的过温完全保护电路）
应用领域
※ 高效率降压调节器 ※ 单片开关电压调节器 ※ 正、负电压转换器
典型应用（固定输出）
LM2596□-5.0
１
管脚图
LM2596 开关电压调节器 SEPTEMBER， 2004
lm2596中文资料
VFB
反馈电压
0.2A≤ILOAD≤3A
VOUT 调为 3V， 电路图见图 1
η
效率
VIN=25V，VOUT =3V， ILOAD=3A
VIN=25V，VOUT =15V，ILOAD=3A
电气特性（所有输出）
典型值（2） 极限值（3）
单位
12.0
88 1.230
73 90
11.52/11.40 12.48/12.60
特点
※ 3.3V、5V、12V 的固定电压输出和可调电压输出 ※ 可调输出电压范围 1.2V～37V±4% ※ 输出线性好且负载可调节 ※ 输出电流可高达 3A ※ 输入电压可高达 40V ※ 采用 150KHz 的内部振荡频率，属于第二代开关电压调节器，功耗小、效率高 ※ 低功耗待机模式，IQ 的典型值为 80μA ※ TTL 断电能力 ※ 具有过热保护和限流保护功能 ※ 封装形式：TO-220（T）和 TO-263（S） ※ 外围电路简单，仅需 4 个外接元件， 且使用容易购买的标准电感
５
TO-263 封装（S）尺寸图
单位：英寸/毫米
TO-220 封装（T）尺寸图
单位：英寸/毫米
６
设计步骤及实例
固定输出调节器的设计步骤
条件：VOUT=3.3（或 5 、或 12）V , VIN（max）为最大直流输入电压, ILOAD（max）为最大负载电流 步骤： 1. 电感的选择（L1） A． 要根据图 4、图 5 和图 6 所示的数据选择电感的适当值（分别对应输出电压为 3.3V、5V 和 12V），对于所有的
符号
参量
器件参数
Ib
反馈偏置电流
fO
振荡器频率
VSAT
lm2596-3.3__LM2596-ADJ_LM2596-12_LV2596-3.3_中文资料
见注 9
5 10
mA mA(max)
ISTBY
待机静电流
ON/OFF 脚=5V（OFF）（9）
80
μA
200/250
μA(max)
３
符号
参量
条件
θJC
θJA
θJA
热阻
θJA
θJA
ON/OFF 控制 （ 测试电路见图 1）
TO-220 或 TO-263 TO-263（10） TO-263（11） TO-263（12） TO-263（13）
V V(max)
最大工作周期（ON） DC
最小工作周期(OFF）
见注 7 见注 8
100
%
0
%
ICL
极限电流
峰值电流（6，7）
4.5 3.6/3.4
A A(min)
6.9/7.5
A(max)
输出为 0V（6，8）
50
μA(max)
IL
输出漏电流
输出为-1V（9）
2 30
mA mA(max)
IQ
静电流
特点
※ 3.3V、5V、12V 的固定电压输出和可调电压输出 ※ 可调输出电压范围 1.2V～37V±4% ※ 输出线性好且负载可调节 ※ 输出电流可高达 3A ※ 输入电压可高达 40V ※ 采用 150KHz 的内部振荡频率，属于第二代开关电压调节器，功耗小、效率高 ※ 低功耗待机模式，IQ 的典型值为 80μA ※ TTL 断电能力 ※ 具有过热保护和限流保护功能 ※ 封装形式：TO-220（T）和 TO-263（S） ※ 外围电路简单，仅需 4 个外接元件， 且使用容易购买的标准电感
ON/OFF 脚逻辑输入
LM2596R-3.3中文资料
元器件交易网3.0A, 150Khz, Step-Down Switching RegulatorFEATURES3.3V, 5.0V, 12V, 15V, and Adjustable Output Versions Adjustable Version Output Voltage Range, 1.23 to 37V +/- 4%. Maximum Over Line and Load Conditions Guaranteed 3.0A Output Current Wide Input Voltage Range Requires Only 4 External Components 150Khz Fixed Frequency Internal Oscillator TTL Shutdown Capability, Low Power Standby Mode High Efficiency Uses Readily Available Standard Inductors Thermal Shutdown and Current Limit Protection Moisture Sensitivity Level(MSL) Equals1 TO-263(D2) TO-220V TO-220LM2596ApplicationsSimple High-Efficiency Step-Down(Buck) Regulator Efficient Pre-Regulator for Linear Regulators On-Card Switching Regulators Positive to Negative Converter(Buck-Boost) Negative Step-Up Converters Power Supply for Battery Chargers1. 2. 3. 4. 5. Vin Output Ground Feedback On/OffDESCRIPTIONThe LM2596 series of regulators are monolithic integrated circuits ideally suited for easy and convenient design of a step-down switching regualtor(buck converter). All circuits of this series are capable of driving a 3.0A load with excellent line and load regulation. These devices are available in fixed output voltages of 3.3V, 5.0V,12V, 15V, and an adjustable output version.ORDERING INFORMATIONDevice LM2596T-X.X LM2596TV-X.X LM2596R Marking LM2596T-X.X LM2596T-X.X LM2596R-X.X Package TO-220 TO-220V TO-263These regulatiors were designed to minimize the number of externalcomponents to simplify the power supply design. Standard series of inductors optimized for use with the LM2576 are offered by several different inductor manufacturers. Since the LM2596 converter is a switch-mode power supply, its efficiency is significantly higher in comparison with popular three-terminal limear reguators, especially with higher input voltages. In many cases, the power dissipated is so low that no heatsink is required or its size could be reduced dramatically. A standard series of inductors optimized for use with the LM2596 are available from several different manufacturers. This feature greatly simplifies the design of switch-mode power supplies. The LM2596 features include a guaranteed +/- 4% tolerance on output voltage within specified input voltages and output load conditions, and +/-15% on the oscillator frequency (+/- 2% over 0oC to 125 oC). External shutdown is included, featuring 80 uA(typical) standby current. The output switch includes cycle-bycycle current limiting, as well as thermal shutdown for full protection under fault conditions.HTC1Oct 2004 - Rev 0元器件交易网3.0A, 15V, Step-Down Switching RegulatorTypical Application (Fixed Output Voltage Versions)LM2596LM2596-5.033 uH680 uF1N5824220 uFFigure 1. Block Diagram and Typical ApplicationABSOLUTE MAXIMUM RATINGS(Absolute Maximum Ratings indicate limits beyond which damage to the device may occur.)Power DissipationTO-220, 5-LeadThermal Resistance, Junction-to-Ambient Thermal Resistance, Junction-to-caseTO-263Thermal Resistance, Junction-to-Ambient Thermal Resistance, Junction-to-caseHTC2Oct 2004 - Rev 0元器件交易网3.0A, 15V, Step-Down Switching RegulatorLM2596OPERATING RATINGS (Operating Ratings indicate conditions for which the device is intended to befunctional, but do not guarantee specific performance limits. For guaranteed specifications and test conditions, see the Electrical Characteristics.)ELECTRICAL CHARACTERISTICS / SYSTEM PARAMETERS ([Note 1] Test Circuit Figure 2) (Unless otherwise specified, Vin = 12 V for the 3.3 V, 5.0 V, and Adjustable version, Vin = 25 V for the 12 V version, and Vin = 30 V for the 15 V version. ILoad = 500 mA. For typical values TJ = 25°C, for min/max values TJ is the operating junction temperature range that applies [Note 2], unless otherwise noted.)LM2596-3.3 ([ Note 1]. Test Circuit Figure 2 )73 LM2596-5.0 ([ Note 1]. Test Circuit Figure 2 ) 180 LM2596-12 ([ Note 1]. Test Circuit Figure 2 )90 LM2596-15 ([ Note 1]. Test Circuit Figure 2 )98 LM2596-ADJ ([ Note 1]. Test Circuit Figure 2 )73HTC3Oct 2004 - Rev 0元器件交易网3.0A, 15V, Step-Down Switching RegulatorELECTRICAL CHARACTERISTICS / Device ParametersLM2596(Unless otherwise specified, Vin = 12 V for the 3.3 V, 5.0 V, and Adjustable version, Vin = 25 V for the 12 V version, and Vin = 30 V for the 15 V version. ILoad = 500 mA. For typical values Tj = 25°C, for min/max values Tj is the operating junction temperature range that applies [Note 2], unless otherwise noted.)10 0 127 110 15050 100 173 1731.16 01.4 1.53.6 3.4100 4.5 6.9 7.5 50 30 1002 5 00 2 0 2.0 2.0 2 V LOGIC = 2.5V (Regulator OFF) V LOGIC = 0.5V (Regulator ON) 5 0.02 1.3 1.32500.6 0.6 15 5.001. External components such as the catch diode, inductor, input and output capacitors can affect switching regulator system performance. When the LM2596 is used as shown in the Figure 1 test circuit, system performance will be as shown in system parameters section . 2. Tested junction temperature range for the LM2596 : TLOW = –0°C THIGH = +125°C 3. The oscillator frequency reduces to approximately 18 kHz in the event of an output short or an overload which causes the regulated output voltage to drop approximately 40% from the nominal output voltage. This self protection feature lowers the average dissipation of the IC by lowering the minimum duty cycle from 5% down to approximately 2%. 4. Output (Pin 2) sourcing current. No diode, inductor or capacitor connected to output pin. 5. Feedback (Pin 4) removed from output and connected to 0 V. 6. Feedback (Pin 4) removed from output and connected to +12 V for the Adjustable, 3.3 V, and 5.0V ersions, and +25 V for the 12 V and15 V versions, to force the output transistor “off”. 7. Vin = 40 V.HTC4Oct 2004 - Rev 0元器件交易网3.0A, 15V, Step-Down Switching RegulatorTYPICAL PERFORMANCE CHARACTERISTICS (Circuit of Figure 2)LM2596HTC5Oct 2004 - Rev 0元器件交易网3.0A, 15V, Step-Down Switching RegulatorTYPICAL PERFORMANCE CHARACTERISTICS (Circuit of Figure 2)Feedback Pin Bias CurrentLM2596HTC6Oct 2004 - Rev 0元器件交易网3.0A, 15V, Step-Down Switching RegulatorTest Circuit and Layout GuidelinesLM2596Figure 2. Typical Test Circuits and Layout GuideAs in any switching regulator, layout is very important. Rapidly switching currents associated with wiring inductance can generate voltage transients which can cause problems. For minimal inductance and ground loops, the wires indicated by heavy lines should be wide printed circuit traces and should be kept as short as possible. For best results, external components should be located as close to the switcher lC as possible using ground plane construction or single point grounding. If open core inductors are used, special care must be taken as to the location and positioning of this type of inductor. Allowing the inductor flux to intersect sensitive feedback, lC groundpath and COUT wiring can cause problems. When using the adjustable version, special care must be taken as to the location of the feedback resistors and the associated wiring. Physically locate both resistors near the IC, and route the wiring away from the inductor, especially an open core type of inductor.HTC7Oct 2004 - Rev 0元器件交易网3.0A, 15V, Step-Down Switching RegulatorLM2596PIN FUNCTION DESCRIPTION Symbol 1VinDescription This pin is the positive input supply for the LM2596 step–down switching23 45regulator.In order to minimize voltage transients and to supply the switching currents needed by the regulator, a suitable input bypass capacitor must be present .(Cin in Figure 1). Output This is the emitter of the internal switch. The saturation voltage Vsat of this output switch is typically 1.5 V. It should be kept in mind that the PCB area connected to this pin should be kept to a minimum in order to minimize coupling to sensitive circuitry. Circuit ground pin. See the information about the printed circuit board layout. Gnd Feedback This pin senses regulated output voltage to complete the feedback loop. The signal is divided by the internal resistor divider network R2, R1 and applied to the non–inverting input of the internal error amplifier. In the Adjustable version of the LM2596 switching regulator this pin is the direct input of the error amplifier and the resistor network R2, R1 is connected externally to allow programming of the output voltage. ON/OFF It allows the switching regulator circuit to be shut down using logic level signals, thus dropping the total input supply current to approximately 80 mA. The threshold voltage is typically 1.4 V. Applying a voltage above this value (up to +Vin) shuts the regulator off. If the voltage applied to this pin is lower than 1.4V or if this pin is left open, the regulator will be in the "on" conditionHTC8Oct 2004 - Rev 0元器件交易网3.0A, 15V, Step-Down Switching RegulatorLM2596PACKAGES DIMENSION : TO220-5LHTC9Oct 2004 - Rev 0元器件交易网3.0A, 15V, Step-Down Switching RegulatorPACKAGES DIMENSION : TO220V-5LLM2596HTC10Oct 2004 - Rev 0元器件交易网3.0A, 15V, Step-Down Switching RegulatorLM2596PACKAGES DIMENSION : TO263-5LHTC11Oct 2004 - Rev 0。
LM2596TADJG中文资料
LM2596Product Preview3.0 A, Step-Down Switching RegulatorThe LM2596 regulator is monolithic integrated circuit ideally suited for easy and convenient design of a step−down switching regulator (buck converter). It is capable of driving a 3.0 A load with excellent line and load regulation. This device is available in adjustable output version and it is internally compensated to minimize the number of external components to simplify the power supply design.Since LM2596 converter is a switch−mode power supply, its efficiency is significantly higher in comparison with popular three−terminal linear regulators, especially with higher input voltages. The LM2596 operates at a switching frequency of 150 kHz thus allowing smaller sized filter components than what would be needed with lower frequency switching regulators. Available in a standard 5−lead TO−220 package with several different lead bend options, and D2PAK surface mount package.The other features include a guaranteed $4% tolerance on output voltage within specified input voltages and output load conditions, and $15% on the oscillator frequency. External shutdown is included, featuring 80 m A (typical) standby current. Self protection features include switch cycle−by−cycle current limit for the output switch, as well as thermal shutdown for complete protection under fault conditions.Features•Adjustable Output Versions 1.23 V − 37 V •Guaranteed 3.0 A Output Load Current•Wide Input V oltage Range up to 40 V•150 kHz Fixed Frequency Internal Oscillator•TTL Shutdown Capability•Low Power Standby Mode, typ 80 m A•Thermal Shutdown and Current Limit Protection •Internal Loop Compensation•Moisture Sensitivity Level (MSL) Equals 1•Pb−Free Packages are AvailableApplications•Simple High−Efficiency Step−Down (Buck) Regulator •Efficient Pre−Regulator for Linear Regulators•On−Card Switching Regulators•Positive to Negative Converter (Buck−Boost)•Negative Step−Up Converters•Power Supply for Battery ChargersThis document contains information on a product under development. ON Semiconductor reserves the right to change or discontinue this product without notice.See detailed ordering and shipping information in the package dimensions section on page 11 of this data sheet.ORDERING INFORMATIONTO−220TV SUFFIXCASE 314BHeatsink surface connected to Pin 3TO−220T SUFFIXCASE 314DPin 1.V in2.Output3.Ground4.Feedback5.ON/OFFD2PAKD2T SUFFIXCASE 936A Heatsink surface (shown as terminal 6 incase outline drawing) is connected to Pin 35See general marking information in the device marking section on page 11 of this data sheet.DEVICE MARKING INFORMATIONFigure 1. Block Diagram and Typical Application8.0 V - 40 V Unregulated DC InputTypical Application (Adjustable Output Voltage Versions)Representative Block Diagram and Typical ApplicationMAXIMUM RATINGSRatingSymbol Value Unit Maximum Supply Voltage V in 45V ON/OFF Pin Input Voltage−−0.3 V ≤ V ≤ +V inV Output Voltage to Ground (Steady −State)−−1.0VPower DissipationCase 314B and 314D (TO −220, 5−Lead)P D Internally LimitedW Thermal Resistance, Junction −to −Ambient R q JA 65°C/W Thermal Resistance, Junction −to −Case R q JC 5.0°C/W Case 936A (D 2PAK)P D Internally LimitedW Thermal Resistance, Junction −to −Ambient R q JA 70°C/W Thermal Resistance, Junction −to −Case R q JC 5.0°C/W Storage Temperature RangeT stg −65 to +150°C Minimum ESD Rating (Human Body Model: C = 100 pF, R = 1.5 k W )− 2.0kV Lead Temperature (Soldering, 10 seconds)−260°C Maximum Junction TemperatureT J150°CStresses exceeding Maximum Ratings may damage the device. Maximum Ratings are stress ratings only. Functional operation above the Recommended Operating Conditions is not implied. Extended exposure to stresses above the Recommended Operating Conditions may affect device reliability.PIN FUNCTION DESCRIPTIONPin Symbol Description (Refer to Figure 1)1V in This pin is the positive input supply for the LM2596 step−down switching regulator. In order to minimize voltage tran-sients and to supply the switching currents needed by the regulator, a suitable input bypass capacitor must bepresent (C in in Figure 1).2Output This is the emitter of the internal switch. The saturation voltage V sat of this output switch is typically 1.5 V. It should be kept in mind that the PCB area connected to this pin should be kept to a minimum in order to minimize coupling tosensitive circuitry.3GND Circuit ground pin. See the information about the printed circuit board layout.4Feedback This pin is the direct input of the error amplifier and the resistor network R2, R1 is connected externally to allow pro-gramming of the output voltage.5ON/OFF It allows the switching regulator circuit to be shut down using logic level signals, thus dropping the total input supply current to approximately 80 m A. The threshold voltage is typically 1.4 V. Applying a voltage above this value (up to+V in) shuts the regulator off. If the voltage applied to this pin is lower than 1.4 V or if this pin is left open, the regulatorwill be in the “on” condition.OPERATING RATINGS (Operating Ratings indicate conditions for which the device is intended to be functional, but do not guarantee specific performance limits. For guaranteed specifications and test conditions, see the Electrical Characteristics.)Rating Symbol Value Unit Operating Junction Temperature Range T J−40 to +125°C Supply Voltage V in 4.5 to 40VSYSTEM PARAMETERSELECTRICAL CHARACTERISTICS Specifications with standard type face are for T J = 25°C, and those with boldface type apply over full Operating Temperature Range −40°C to +125°CCharacteristics Symbol Min Typ Max Unit LM2596 (Note 1, Test Circuit Figure )Feedback Voltage (V in= 12 V, I Load = 0.5 A, V out = 5.0 V, )V FB 1.217 1.23 1.243VFeedback Voltage (8.0 V ≤ V in≤ 40 V, 0.5 A ≤ I Load≤ 3.0 A, V out = 5.0 V)V FB 1.1931.181.2671.28VEfficiency (V in= 12 V, I Load = 3.0 A, V out = 5.0 V)η−73−% Characteristics Symbol Min Typ Max Unit Feedback Bias Current (V out = 5.0 V)I b25100200nAOscillator Frequency( Note 2)f osc135120150165180kHzSaturation Voltage (I out = 3.0 A, Notes 3 and 4)V sat 1.5 1.82.0V Max Duty Cycle (ON) Note 4DC95%Current Limit (Peak Current Notes 2 and 3)I CL 4.23.55.6 6.97.5AOutput Leakage Current (Notes 5 and 6) Output = 0 VOutput = −1.0 V I L0.56.02.020mAQuiescent Current (Note 5)I Q 5.010mAStandby Quiescent Current (ON/OFF Pin = 5.0 V (“off”)) (Note 6)I stby50200250m AON/OFF PIN LOGIC INPUTThreshold Voltage 1.6VV out = 0 V (Regulator OFF)V IH 2.22.4VV out = Nominal Output Voltage (Regulator ON)V IL 1.00.8V ON/OFF Pin Input CurrentON/OFF Pin = 5.0 V (Regulator OFF)I IH−1530m A ON/OFF Pin = 0 V (regulator ON)I IL−0.01 5.0m A 1.External components such as the catch diode, inductor, input and output capacitors can affect switching regulator system performance.When the LM2596 is used as shown in the Figure 15test circuit, system performance will be as shown in system parameters section.2.The oscillator frequency reduces to approximately 30 kHz in the event of an output short or an overload which causes the regulated outputvoltage to drop approximately 40% from the nominal output voltage. This self protection feature lowers the average dissipation of the IC by lowering the minimum duty cycle from 5% down to approximately 2%.3.No diode, inductor or capacitor connected to output pin.4.Feedback (Pin 4) removed from output and connected to 0 V.5.Feedback (Pin 4) removed from output and connected to +12 V to force the output transistor “off”.6.V in = 40 V.I Q , Q U I E S C E N T C U R R E N T (m A )V o u t , O U T P U T V O L T A G E C H A N G E (%)V o u t , O U T P U T V O L T A G E C H A N G E (%), S T A N D B Y Q U I E S C E N T C U R R E N T (T J , JUNCTION TEMPERATURE (°C)I O , O U T P U T C U R R E N T (A )T J , JUNCTION TEMPERATURE (°C)V in , INPUT VOLTAGE (V)V in , INPUT VOLTAGE (V)I N P U T - O U T P U T D I F F E R E N T I A L (V )T J , JUNCTION TEMPERATURE (°C)Figure 2. Normalized Output Voltage T J , JUNCTION TEMPERATURE (°C)Figure 3. Line RegulationFigure 4. Dropout Voltage Figure 5. Current LimitFigure 6. Quiescent Current Figure 7. Standby Quiescent CurrentμA )1.00.60.20-0.2-0.4-1.0 1.41.21.00.80.60.40.20-0.2-0.4-0.66.56.05.55.04.54.02018161412108.06.04.0-0.8-0.60.40.8I s t b yV s a t , S A T U R A T I O N V O L T A G E (V )2.02.53.04.0I b , F E E D B A C K P I N C U R R E N T (n A ), S T A N D B Y Q U I E S C E N T C U R R E N T (μA )I s t b y , I N P U T V O L T A G E (V )T J , JUNCTION TEMPERATURE (°C)SWITCH CURRENT (A)N O R M A L I Z E D F R E Q U E N C Y (%)T J , JUNCTION TEMPERATURE (°C)Figure 8. Standby Quiescent Current V in , INPUT VOLTAGE (V)Figure 9. Switch Saturation VoltageFigure 10. Oscillator FrequencyFigure 11. Minimum Operating VoltageFigure 12. Feedback Pin Current2001801401201008060402001.61.41.21.00.80.60.40.205.04.53.51.51.00.50-50T J , JUNCTION TEMPERATURE (°C)100806040200-20-40-60-80-100125100755025-25-50160V i n −9.0−8.0−7.0−6.0−5.0−4.0−3.0−2.0−1.00.01.0−2.0 A 00ABC 100 m s/DIV2 m s/DIVFigure 13. Switching WaveformsFigure 14. Load Transient ResponseVout = 15 VA: Output Pin Voltage, 10 V/DIV B: Inductor Current, 2.0 A/DIVC: Inductor Current, 2.0 A/DIV, AC −CoupledD: Output Ripple Voltage, 50 mV/dDIV, AC −Coupled Horizontal Time Base: 5.0 m s/DIV50 V 04.0 A 2.0 A 100 mV OutputVoltageChange03.0 A2.0 A 1.0 A4.0 A - 100 mVLoad CurrentDFigure 15. Typical Test CircuitAdjustable Output Voltage Versionsout ref R2R1ǓR2+R1ǒV out V ref 1.0ǓWhere V ref = 1.23 V, R1 between 1.0 k and 5.0 kPCB LAYOUT GUIDELINESAs in any switching regulator, the layout of the printed circuit board is very important. Rapidly switching currents associated with wiring inductance, stray capacitance and parasitic inductance of the printed circuit board traces can generate voltage transients which can generate electromagnetic interferences (EMI) and affect the desired operation. As indicated in the Figure 15, to minimize inductance and ground loops, the length of the leads indicated by heavy lines should be kept as short as possible.For best results, single −point grounding (as indicated) or ground plane construction should be used.On the other hand, the PCB area connected to the Pin 2(emitter of the internal switch) of the LM2596 should be kept to a minimum in order to minimize coupling to sensitive circuitry.Another sensitive part of the circuit is the feedback. It is important to keep the sensitive feedback wiring short. To assure this, physically locate the programming resistors near to the regulator, when using the adjustable version of the LM2596 regulator.DESIGN PROCEDUREBuck Converter BasicsThe LM2596 is a “Buck” or Step −Down Converter which is the most elementary forward −mode converter. Its basic schematic can be seen in Figure 16.The operation of this regulator topology has two distinct time periods. The first one occurs when the series switch is on, the input voltage is connected to the input of the inductor.The output of the inductor is the output voltage, and the rectifier (or catch diode) is reverse biased. During this period, since there is a constant voltage source connected across the inductor, the inductor current begins to linearly ramp upwards, as described by the following equation:I L(on)+ǒV IN *V OUT Ǔt onLDuring this “on” period, energy is stored within the core material in the form of magnetic flux. If the inductor is properly designed, there is sufficient energy stored to carry the requirements of the load during the “off” period.Figure 16. Basic Buck ConverterR LoadPower The next period is the “off” period of the power switch.When the power switch turns off, the voltage across the inductor reverses its polarity and is clamped at one diode voltage drop below ground by the catch diode. The current now flows through the catch diode thus maintaining the load current loop. This removes the stored energy from the inductor. The inductor current during this time is:I L(off)+ǒV OUT *V D Ǔt offLThis period ends when the power switch is once again turned on. Regulation of the converter is accomplished by varying the duty cycle of the power switch. It is possible to describe the duty cycle as follows:d +ton T, where T is the period of switching.For the buck converter with ideal components, the duty cycle can also be described as:d +V outV inFigure 17 shows the buck converter, idealized waveforms of the catch diode voltage and the inductor current.Figure 17. Buck Converter Idealized WaveformsPROCEDURE (ADJUSTABLE OUTPUT VERSION:LM2596)PROCEDURE (ADJUSTABLE OUTPUT VERSION:LM2596) (CONTINUED)ORDERING INFORMATIONDevicePackage Shipping †LM2596TADJG TO −220(Pb −Free)50 Units / Rail LM2596TVADJG TO −220 (F)(Pb −Free)50 Units / Rail LM2596DSADJG D 2PAK (Pb −Free)50 Units / Rail LM2596DSADJR4GD 2PAK (Pb −Free)2500 / Tape & Reel†For information on tape and reel specifications, including part orientation and tape sizes, please refer to our Tape and Reel Packaging Specifications Brochure, BRD8011/D.A = Assembly Location WL = Wafer Lot Y = YearWW = Work WeekG= Pb −Free PackageTO −220TV SUFFIX CASE 314B1MARKING DIAGRAMS5TO −220T SUFFIX CASE 314DD 2PAK D2T SUFFIX CASE 936ALM2596T −ADJ AWLYWWGLM2596T −ADJ AWLYWWGLM2596D2T −ADJ AWLYWWG1515LM2596−ADJ AWLYWWG 15TO −220TV SUFFIX CASE 314B −05ISSUE LM0.10 (0.254)PMT NOTES:1.DIMENSIONING AND TOLERANCING PER ANSI Y14.5M, 1982.2.CONTROLLING DIMENSION: INCH.3.DIMENSION D DOES NOT INCLUDEINTERCONNECT BAR (DAMBAR) PROTRUSION.DIMENSION D INCLUDING PROTRUSION SHALL NOT EXCEED 0.043 (1.092) MAXIMUM.DIM MIN MAX MIN MAX MILLIMETERSINCHES A 0.5720.61314.52915.570B 0.3900.4159.90610.541C 0.1700.180 4.318 4.572D 0.0250.0380.6350.965E 0.0480.055 1.219 1.397F 0.8500.93521.59023.749G 0.067 BSC 1.702 BSC H 0.166 BSC 4.216 BSC J 0.0150.0250.3810.635K 0.900 1.10022.86027.940L 0.3200.3658.1289.271N 0.320 BSC 8.128 BSC Q 0.1400.153 3.556 3.886S ---0.620---15.748U 0.4680.50511.88812.827V ---0.735---18.669W0.0900.1102.286 2.794TO −220T SUFFIX CASE 314D −04ISSUE FMQM0.356 (0.014)T SEATING PLANEDIM MIN MAX MIN MAX MILLIMETERSINCHES A 0.5720.61314.52915.570B 0.3900.4159.90610.541C 0.1700.180 4.318 4.572D 0.0250.0380.6350.965E 0.0480.055 1.219 1.397G 0.067 BSC 1.702 BSC H 0.0870.112 2.210 2.845J 0.0150.0250.3810.635K 0.977 1.04524.81026.543L 0.3200.3658.1289.271Q 0.1400.153 3.556 3.886U0.1050.1172.667 2.972NOTES:1.DIMENSIONING AND TOLERANCING PER ANSI Y14.5M, 1982.2.CONTROLLING DIMENSION: INCH.3.DIMENSION D DOES NOT INCLUDEINTERCONNECT BAR (DAMBAR) PROTRUSION.DIMENSION D INCLUDING PROTRUSION SHALL NOT EXCEED 10.92 (0.043) MAXIMUM.B10.3750.4159.52510.541DETAIL A −AD 2PAK D2T SUFFIX CASE 936A −02ISSUE C5 REF NOTES:1.DIMENSIONING AND TOLERANCING PER ANSI Y14.5M, 1982.2.CONTROLLING DIMENSION: INCH.3.TAB CONTOUR OPTIONAL WITHIN DIMENSIONS A AND K.4.DIMENSIONS U AND V ESTABLISH A MINIMUM MOUNTING SURFACE FOR TERMINAL 6.5.DIMENSIONS A AND B DO NOT INCLUDE MOLD FLASH OR GATE PROTRUSIONS. MOLD FLASH AND GATE PROTRUSIONS NOT TO EXCEED 0.025(0.635) MAXIMUM.DIM A MIN MAX MIN MAX MILLIMETERS 0.3860.4039.80410.236INCHES B 0.3560.3689.0429.347C 0.1700.180 4.318 4.572D 0.0260.0360.6600.914E 0.0450.055 1.143 1.397G 0.067 BSC 1.702 BSC H 0.5390.57913.69114.707K 0.050 REF 1.270 REF L 0.0000.0100.0000.254M 0.0880.102 2.235 2.591N 0.0180.0260.4570.660P 0.0580.0781.473 1.981R 5 REF S 0.116 REF 2.946 REF U 0.200 MIN 5.080 MIN V0.250 MIN6.350 MIN__SCALE 3:1ǒmm inchesǓ*For additional information on our Pb −Free strategy and solderingdetails, please download the ON Semiconductor Soldering and Mounting Techniques Reference Manual, SOLDERRM/D.ON Semiconductor and are registered trademarks of Semiconductor Components Industries, LLC (SCILLC). SCILLC reserves the right to make changes without further notice to any products herein. SCILLC makes no warranty, representation or guarantee regarding the suitability of its products for any particular purpose, nor does SCILLC assume any liability arising out of the application or use of any product or circuit, and specifically disclaims any and all liability, including without limitation special, consequential or incidental damages.“Typical” parameters which may be provided in SCILLC data sheets and/or specifications can and do vary in different applications and actual performance may vary over time. All operating parameters, including “Typicals” must be validated for each customer application by customer’s technical experts. SCILLC does not convey any license under its patent rights nor the rights of others. SCILLC products are not designed, intended, or authorized for use as components in systems intended for surgical implant into the body, or other applications intended to support or sustain life, or for any other application in which the failure of the SCILLC product could create a situation where personal injury or death may occur.Should Buyer purchase or use SCILLC products for any such unintended or unauthorized application, Buyer shall indemnify and hold SCILLC and its officers, employees, subsidiaries,affiliates, and distributors harmless against all claims, costs, damages, and expenses, and reasonable attorney fees arising out of, directly or indirectly, any claim of personal injury or death associated with such unintended or unauthorized use, even if such claim alleges that SCILLC was negligent regarding the design or manufacture of the part. SCILLC is an Equal Opportunity/Affirmative Action Employer. This literature is subject to all applicable copyright laws and is not for resale in any manner.PUBLICATION ORDERING INFORMATION。
lm596中文资料
LM2596开关电压调节器LM2596开关电压调节器是降压型电源管理单片集成电路，能够输出3A的驱动电流，同时具有很好的线性和负载调节特性。
固定输出版本有3.3V、5V、12V，可调版本可以输出小于37V的各种电压。
该器件内部集成频率补偿和固定频率发生器，开关频率为150KHz，与低频开关调节器相比较，可以使用更小规格的滤波元件。
由于该器件只需4个外接元件，可以使用通用的标准电感，这更优化了LM2596的使用，极大地简化了开关电源电路的设计。
其封装形式包括标准的5脚TO-220封装（DIP）和5脚TO-263表贴封装（SMD）。
该器件还有其他一些特点：在特定的输入电压和输出负载的条件下，输出电压的误差可以保证在±4%的范围内，振荡频率误差在±15%的范围内；可以用仅80μA的待机电流，实现外部断电；具有自我保护电路（一个两级降频限流保护和一个在异常情况下断电的过温完全保护电路）特点Ć 3.3V、5V、12V的固定电压输出和可调电压输出Ć可调输出电压范围1.2V～37V±4%Ć输出线性好且负载可调节Ć输出电流可高达3AĆ输入电压可高达40VĆ采用150KHz的内部振荡频率，属于第二代开关电压调节器，功耗小、效率高Ć低功耗待机模式，I Q的典型值为80μAĆTTL断电能力Ć具有过热保护和限流保护功能Ć封装形式：TO-220（T）和TO-263（S）Ć外围电路简单，仅需4个外接元件，且使用容易购买的标准电感应用领域Ć高效率降压调节器Ć单片开关电压调节器Ć正、负电压转换器典型应用（固定输出）LM2596□-5.0管脚图极限参数名称范围单位最大电源电压45V 脚输入电压-0.3～25V “反馈”脚电压-0.3～25V 到地的输出电压（静态）-1V 功耗由内部限定--储存温度-65～150℃静电释放（人体放电1）2000V 气流焊（60秒）215℃TO-263红外线焊接（10秒）245℃焊接时的管脚温度TO-220波峰焊/电烙铁焊接（10秒）260℃最高结温150℃温度范围-40～125℃工作条件电源电压4.5～40V注1：人体放电模式相当于一个100PF 的电容通过一个1.5K 的电阻向每个管脚放电。
lm2596中文资料
lm2596中文资料1. 概述lm2596是一款高效率开关电源稳压器芯片，广泛应用于电子设备中对直流电压进行稳定调整的场合。
本文档将详细介绍lm2596的特性、工作原理、应用场景以及使用注意事项。
2. 特性•宽输入电压范围：4V-40V•可调输出电压范围：1.23V-37V•高效率：可达到92%•最大输出电流：3A•过热保护功能3. 工作原理lm2596采用了开关稳压器的工作原理，通过周期性地开关和断开电流流通路径，将输入电压转换为稳定的输出电压。
其主要原理如下：1.输入电压通过电感和开关管传导到输出端，同时电容储存能量。
2.控制器检测输出电压，如果低于设定值，则控制开关管开启，使电流通过电感传输到输出端，提供稳定的输出电压。
3.如果输出电压高于设定值，则控制开关管关闭，切断电流流动。
这种周期性的开关和断开电路，可以通过控制开关管的开启时间和关闭时间，来调整输出电压的稳定性和精确度。
4. 应用场景lm2596广泛应用于各种需要稳定直流电压的场合，以下是lm2596常见的应用场景：4.1 电子设备稳压电源lm2596可以根据需要调整输出电压，可以在电子设备中作为稳压电源芯片使用。
它可以将输入电压调整为稳定的输出电压，以供电子设备正常运行。
4.2 LED照明由于lm2596具有高效率和可调输出电压的特性，非常适合用于LED照明应用。
lm2596可以将输入电压调整为适合LED灯的电压，提供稳定的电源以驱动LED照明。
4.3 高频电源lm2596的高效率和宽输入电压范围，使其非常适合用于高频电源应用。
lm2596可以将输入电压转换为稳定的高频输出，满足高频电源的需求。
5. 使用注意事项在使用lm2596时，请注意以下事项：1.输入电压不要超过40V，否则可能导致芯片过载损坏。
2.充分考虑散热问题，尽量避免芯片过热，建议在芯片周围预留散热空间。
3.在使用lm2596时，应按照芯片的使用说明进行正确的电路设计和连接。
LM2596T中文资料
元器件交易网3.0A, 150Khz, Step-Down Switching RegulatorFEATURES3.3V, 5.0V, 12V, 15V, and Adjustable Output Versions Adjustable Version Output Voltage Range, 1.23 to 37V +/- 4%. Maximum Over Line and Load Conditions Guaranteed 3.0A Output Current Wide Input Voltage Range Requires Only 4 External Components 150Khz Fixed Frequency Internal Oscillator TTL Shutdown Capability, Low Power Standby Mode High Efficiency Uses Readily Available Standard Inductors Thermal Shutdown and Current Limit Protection Moisture Sensitivity Level(MSL) Equals1 TO-263(D2) TO-220V TO-220LM2596ApplicationsSimple High-Efficiency Step-Down(Buck) Regulator Efficient Pre-Regulator for Linear Regulators On-Card Switching Regulators Positive to Negative Converter(Buck-Boost) Negative Step-Up Converters Power Supply for Battery Chargers1. 2. 3. 4. 5. Vin Output Ground Feedback On/OffDESCRIPTIONThe LM2596 series of regulators are monolithic integrated circuits ideally suited for easy and convenient design of a step-down switching regualtor(buck converter). All circuits of this series are capable of driving a 3.0A load with excellent line and load regulation. These devices are available in fixed output voltages of 3.3V, 5.0V,12V, 15V, and an adjustable output version.ORDERING INFORMATIONDevice LM2596T-X.X LM2596TV-X.X LM2596R Marking LM2596T-X.X LM2596T-X.X LM2596R-X.X Package TO-220 TO-220V TO-263These regulatiors were designed to minimize the number of externalcomponents to simplify the power supply design. Standard series of inductors optimized for use with the LM2576 are offered by several different inductor manufacturers. Since the LM2596 converter is a switch-mode power supply, its efficiency is significantly higher in comparison with popular three-terminal limear reguators, especially with higher input voltages. In many cases, the power dissipated is so low that no heatsink is required or its size could be reduced dramatically. A standard series of inductors optimized for use with the LM2596 are available from several different manufacturers. This feature greatly simplifies the design of switch-mode power supplies. The LM2596 features include a guaranteed +/- 4% tolerance on output voltage within specified input voltages and output load conditions, and +/-15% on the oscillator frequency (+/- 2% over 0oC to 125 oC). External shutdown is included, featuring 80 uA(typical) standby current. The output switch includes cycle-bycycle current limiting, as well as thermal shutdown for full protection under fault conditions.HTC1Oct 2004 - Rev 0元器件交易网3.0A, 15V, Step-Down Switching RegulatorTypical Application (Fixed Output Voltage Versions)LM2596LM2596-5.033 uH680 uF1N5824220 uFFigure 1. Block Diagram and Typical ApplicationABSOLUTE MAXIMUM RATINGS(Absolute Maximum Ratings indicate limits beyond which damage to the device may occur.)Power DissipationTO-220, 5-LeadThermal Resistance, Junction-to-Ambient Thermal Resistance, Junction-to-caseTO-263Thermal Resistance, Junction-to-Ambient Thermal Resistance, Junction-to-caseHTC2Oct 2004 - Rev 0元器件交易网3.0A, 15V, Step-Down Switching RegulatorLM2596OPERATING RATINGS (Operating Ratings indicate conditions for which the device is intended to befunctional, but do not guarantee specific performance limits. For guaranteed specifications and test conditions, see the Electrical Characteristics.)ELECTRICAL CHARACTERISTICS / SYSTEM PARAMETERS ([Note 1] Test Circuit Figure 2) (Unless otherwise specified, Vin = 12 V for the 3.3 V, 5.0 V, and Adjustable version, Vin = 25 V for the 12 V version, and Vin = 30 V for the 15 V version. ILoad = 500 mA. For typical values TJ = 25°C, for min/max values TJ is the operating junction temperature range that applies [Note 2], unless otherwise noted.)LM2596-3.3 ([ Note 1]. Test Circuit Figure 2 )73 LM2596-5.0 ([ Note 1]. Test Circuit Figure 2 ) 180 LM2596-12 ([ Note 1]. Test Circuit Figure 2 )90 LM2596-15 ([ Note 1]. Test Circuit Figure 2 )98 LM2596-ADJ ([ Note 1]. Test Circuit Figure 2 )73HTC3Oct 2004 - Rev 0元器件交易网3.0A, 15V, Step-Down Switching RegulatorELECTRICAL CHARACTERISTICS / Device ParametersLM2596(Unless otherwise specified, Vin = 12 V for the 3.3 V, 5.0 V, and Adjustable version, Vin = 25 V for the 12 V version, and Vin = 30 V for the 15 V version. ILoad = 500 mA. For typical values Tj = 25°C, for min/max values Tj is the operating junction temperature range that applies [Note 2], unless otherwise noted.)10 0 127 110 15050 100 173 1731.16 01.4 1.53.6 3.4100 4.5 6.9 7.5 50 30 1002 5 00 2 0 2.0 2.0 2 V LOGIC = 2.5V (Regulator OFF) V LOGIC = 0.5V (Regulator ON) 5 0.02 1.3 1.32500.6 0.6 15 5.001. External components such as the catch diode, inductor, input and output capacitors can affect switching regulator system performance. When the LM2596 is used as shown in the Figure 1 test circuit, system performance will be as shown in system parameters section . 2. Tested junction temperature range for the LM2596 : TLOW = –0°C THIGH = +125°C 3. The oscillator frequency reduces to approximately 18 kHz in the event of an output short or an overload which causes the regulated output voltage to drop approximately 40% from the nominal output voltage. This self protection feature lowers the average dissipation of the IC by lowering the minimum duty cycle from 5% down to approximately 2%. 4. Output (Pin 2) sourcing current. No diode, inductor or capacitor connected to output pin. 5. Feedback (Pin 4) removed from output and connected to 0 V. 6. Feedback (Pin 4) removed from output and connected to +12 V for the Adjustable, 3.3 V, and 5.0V ersions, and +25 V for the 12 V and15 V versions, to force the output transistor “off”. 7. Vin = 40 V.HTC4Oct 2004 - Rev 0元器件交易网3.0A, 15V, Step-Down Switching RegulatorTYPICAL PERFORMANCE CHARACTERISTICS (Circuit of Figure 2)LM2596HTC5Oct 2004 - Rev 0元器件交易网3.0A, 15V, Step-Down Switching RegulatorTYPICAL PERFORMANCE CHARACTERISTICS (Circuit of Figure 2)Feedback Pin Bias CurrentLM2596HTC6Oct 2004 - Rev 0元器件交易网3.0A, 15V, Step-Down Switching RegulatorTest Circuit and Layout GuidelinesLM2596Figure 2. Typical Test Circuits and Layout GuideAs in any switching regulator, layout is very important. Rapidly switching currents associated with wiring inductance can generate voltage transients which can cause problems. For minimal inductance and ground loops, the wires indicated by heavy lines should be wide printed circuit traces and should be kept as short as possible. For best results, external components should be located as close to the switcher lC as possible using ground plane construction or single point grounding. If open core inductors are used, special care must be taken as to the location and positioning of this type of inductor. Allowing the inductor flux to intersect sensitive feedback, lC groundpath and COUT wiring can cause problems. When using the adjustable version, special care must be taken as to the location of the feedback resistors and the associated wiring. Physically locate both resistors near the IC, and route the wiring away from the inductor, especially an open core type of inductor.HTC7Oct 2004 - Rev 0元器件交易网3.0A, 15V, Step-Down Switching RegulatorLM2596PIN FUNCTION DESCRIPTION Symbol 1VinDescription This pin is the positive input supply for the LM2596 step–down switching23 45regulator.In order to minimize voltage transients and to supply the switching currents needed by the regulator, a suitable input bypass capacitor must be present .(Cin in Figure 1). Output This is the emitter of the internal switch. The saturation voltage Vsat of this output switch is typically 1.5 V. It should be kept in mind that the PCB area connected to this pin should be kept to a minimum in order to minimize coupling to sensitive circuitry. Circuit ground pin. See the information about the printed circuit board layout. Gnd Feedback This pin senses regulated output voltage to complete the feedback loop. The signal is divided by the internal resistor divider network R2, R1 and applied to the non–inverting input of the internal error amplifier. In the Adjustable version of the LM2596 switching regulator this pin is the direct input of the error amplifier and the resistor network R2, R1 is connected externally to allow programming of the output voltage. ON/OFF It allows the switching regulator circuit to be shut down using logic level signals, thus dropping the total input supply current to approximately 80 mA. The threshold voltage is typically 1.4 V. Applying a voltage above this value (up to +Vin) shuts the regulator off. If the voltage applied to this pin is lower than 1.4V or if this pin is left open, the regulator will be in the "on" conditionHTC8Oct 2004 - Rev 0元器件交易网3.0A, 15V, Step-Down Switching RegulatorLM2596PACKAGES DIMENSION : TO220-5LHTC9Oct 2004 - Rev 0元器件交易网3.0A, 15V, Step-Down Switching RegulatorPACKAGES DIMENSION : TO220V-5LLM2596HTC10Oct 2004 - Rev 0元器件交易网3.0A, 15V, Step-Down Switching RegulatorLM2596PACKAGES DIMENSION : TO263-5LHTC11Oct 2004 - Rev 0。
lm2596中文资料_数据手册_参数
LM2596R-5.0中文资料
元器件交易网3.0A, 150Khz, Step-Down Switching RegulatorFEATURES3.3V, 5.0V, 12V, 15V, and Adjustable Output Versions Adjustable Version Output Voltage Range, 1.23 to 37V +/- 4%. Maximum Over Line and Load Conditions Guaranteed 3.0A Output Current Wide Input Voltage Range Requires Only 4 External Components 150Khz Fixed Frequency Internal Oscillator TTL Shutdown Capability, Low Power Standby Mode High Efficiency Uses Readily Available Standard Inductors Thermal Shutdown and Current Limit Protection Moisture Sensitivity Level(MSL) Equals1 TO-263(D2) TO-220V TO-220LM2596ApplicationsSimple High-Efficiency Step-Down(Buck) Regulator Efficient Pre-Regulator for Linear Regulators On-Card Switching Regulators Positive to Negative Converter(Buck-Boost) Negative Step-Up Converters Power Supply for Battery Chargers1. 2. 3. 4. 5. Vin Output Ground Feedback On/OffDESCRIPTIONThe LM2596 series of regulators are monolithic integrated circuits ideally suited for easy and convenient design of a step-down switching regualtor(buck converter). All circuits of this series are capable of driving a 3.0A load with excellent line and load regulation. These devices are available in fixed output voltages of 3.3V, 5.0V,12V, 15V, and an adjustable output version.ORDERING INFORMATIONDevice LM2596T-X.X LM2596TV-X.X LM2596R Marking LM2596T-X.X LM2596T-X.X LM2596R-X.X Package TO-220 TO-220V TO-263These regulatiors were designed to minimize the number of externalcomponents to simplify the power supply design. Standard series of inductors optimized for use with the LM2576 are offered by several different inductor manufacturers. Since the LM2596 converter is a switch-mode power supply, its efficiency is significantly higher in comparison with popular three-terminal limear reguators, especially with higher input voltages. In many cases, the power dissipated is so low that no heatsink is required or its size could be reduced dramatically. A standard series of inductors optimized for use with the LM2596 are available from several different manufacturers. This feature greatly simplifies the design of switch-mode power supplies. The LM2596 features include a guaranteed +/- 4% tolerance on output voltage within specified input voltages and output load conditions, and +/-15% on the oscillator frequency (+/- 2% over 0oC to 125 oC). External shutdown is included, featuring 80 uA(typical) standby current. The output switch includes cycle-bycycle current limiting, as well as thermal shutdown for full protection under fault conditions.HTC1Oct 2004 - Rev 0元器件交易网3.0A, 15V, Step-Down Switching RegulatorTypical Application (Fixed Output Voltage Versions)LM2596LM2596-5.033 uH680 uF1N5824220 uFFigure 1. Block Diagram and Typical ApplicationABSOLUTE MAXIMUM RATINGS(Absolute Maximum Ratings indicate limits beyond which damage to the device may occur.)Power DissipationTO-220, 5-LeadThermal Resistance, Junction-to-Ambient Thermal Resistance, Junction-to-caseTO-263Thermal Resistance, Junction-to-Ambient Thermal Resistance, Junction-to-caseHTC2Oct 2004 - Rev 0元器件交易网3.0A, 15V, Step-Down Switching RegulatorLM2596OPERATING RATINGS (Operating Ratings indicate conditions for which the device is intended to befunctional, but do not guarantee specific performance limits. For guaranteed specifications and test conditions, see the Electrical Characteristics.)ELECTRICAL CHARACTERISTICS / SYSTEM PARAMETERS ([Note 1] Test Circuit Figure 2) (Unless otherwise specified, Vin = 12 V for the 3.3 V, 5.0 V, and Adjustable version, Vin = 25 V for the 12 V version, and Vin = 30 V for the 15 V version. ILoad = 500 mA. For typical values TJ = 25°C, for min/max values TJ is the operating junction temperature range that applies [Note 2], unless otherwise noted.)LM2596-3.3 ([ Note 1]. Test Circuit Figure 2 )73 LM2596-5.0 ([ Note 1]. Test Circuit Figure 2 ) 180 LM2596-12 ([ Note 1]. Test Circuit Figure 2 )90 LM2596-15 ([ Note 1]. Test Circuit Figure 2 )98 LM2596-ADJ ([ Note 1]. Test Circuit Figure 2 )73HTC3Oct 2004 - Rev 0元器件交易网3.0A, 15V, Step-Down Switching RegulatorELECTRICAL CHARACTERISTICS / Device ParametersLM2596(Unless otherwise specified, Vin = 12 V for the 3.3 V, 5.0 V, and Adjustable version, Vin = 25 V for the 12 V version, and Vin = 30 V for the 15 V version. ILoad = 500 mA. For typical values Tj = 25°C, for min/max values Tj is the operating junction temperature range that applies [Note 2], unless otherwise noted.)10 0 127 110 15050 100 173 1731.16 01.4 1.53.6 3.4100 4.5 6.9 7.5 50 30 1002 5 00 2 0 2.0 2.0 2 V LOGIC = 2.5V (Regulator OFF) V LOGIC = 0.5V (Regulator ON) 5 0.02 1.3 1.32500.6 0.6 15 5.001. External components such as the catch diode, inductor, input and output capacitors can affect switching regulator system performance. When the LM2596 is used as shown in the Figure 1 test circuit, system performance will be as shown in system parameters section . 2. Tested junction temperature range for the LM2596 : TLOW = –0°C THIGH = +125°C 3. The oscillator frequency reduces to approximately 18 kHz in the event of an output short or an overload which causes the regulated output voltage to drop approximately 40% from the nominal output voltage. This self protection feature lowers the average dissipation of the IC by lowering the minimum duty cycle from 5% down to approximately 2%. 4. Output (Pin 2) sourcing current. No diode, inductor or capacitor connected to output pin. 5. Feedback (Pin 4) removed from output and connected to 0 V. 6. Feedback (Pin 4) removed from output and connected to +12 V for the Adjustable, 3.3 V, and 5.0V ersions, and +25 V for the 12 V and15 V versions, to force the output transistor “off”. 7. Vin = 40 V.HTC4Oct 2004 - Rev 0元器件交易网3.0A, 15V, Step-Down Switching RegulatorTYPICAL PERFORMANCE CHARACTERISTICS (Circuit of Figure 2)LM2596HTC5Oct 2004 - Rev 0元器件交易网3.0A, 15V, Step-Down Switching RegulatorTYPICAL PERFORMANCE CHARACTERISTICS (Circuit of Figure 2)Feedback Pin Bias CurrentLM2596HTC6Oct 2004 - Rev 0元器件交易网3.0A, 15V, Step-Down Switching RegulatorTest Circuit and Layout GuidelinesLM2596Figure 2. Typical Test Circuits and Layout GuideAs in any switching regulator, layout is very important. Rapidly switching currents associated with wiring inductance can generate voltage transients which can cause problems. For minimal inductance and ground loops, the wires indicated by heavy lines should be wide printed circuit traces and should be kept as short as possible. For best results, external components should be located as close to the switcher lC as possible using ground plane construction or single point grounding. If open core inductors are used, special care must be taken as to the location and positioning of this type of inductor. Allowing the inductor flux to intersect sensitive feedback, lC groundpath and COUT wiring can cause problems. When using the adjustable version, special care must be taken as to the location of the feedback resistors and the associated wiring. Physically locate both resistors near the IC, and route the wiring away from the inductor, especially an open core type of inductor.HTC7Oct 2004 - Rev 0元器件交易网3.0A, 15V, Step-Down Switching RegulatorLM2596PIN FUNCTION DESCRIPTION Symbol 1VinDescription This pin is the positive input supply for the LM2596 step–down switching23 45regulator.In order to minimize voltage transients and to supply the switching currents needed by the regulator, a suitable input bypass capacitor must be present .(Cin in Figure 1). Output This is the emitter of the internal switch. The saturation voltage Vsat of this output switch is typically 1.5 V. It should be kept in mind that the PCB area connected to this pin should be kept to a minimum in order to minimize coupling to sensitive circuitry. Circuit ground pin. See the information about the printed circuit board layout. Gnd Feedback This pin senses regulated output voltage to complete the feedback loop. The signal is divided by the internal resistor divider network R2, R1 and applied to the non–inverting input of the internal error amplifier. In the Adjustable version of the LM2596 switching regulator this pin is the direct input of the error amplifier and the resistor network R2, R1 is connected externally to allow programming of the output voltage. ON/OFF It allows the switching regulator circuit to be shut down using logic level signals, thus dropping the total input supply current to approximately 80 mA. The threshold voltage is typically 1.4 V. Applying a voltage above this value (up to +Vin) shuts the regulator off. If the voltage applied to this pin is lower than 1.4V or if this pin is left open, the regulator will be in the "on" conditionHTC8Oct 2004 - Rev 0元器件交易网3.0A, 15V, Step-Down Switching RegulatorLM2596PACKAGES DIMENSION : TO220-5LHTC9Oct 2004 - Rev 0元器件交易网3.0A, 15V, Step-Down Switching RegulatorPACKAGES DIMENSION : TO220V-5LLM2596HTC10Oct 2004 - Rev 0元器件交易网3.0A, 15V, Step-Down Switching RegulatorLM2596PACKAGES DIMENSION : TO263-5LHTC11Oct 2004 - Rev 0。
中文资料 LM2596电源降压调整器
LM2596电源降压调整器（150KHz，3A）英文文章名：LM2596 SIMPLE SWITCHER® Power Converter 150 kHz3A Step-Down Voltage Regulator文章出处：版本号：DS012583 日期：2002年5月摘录人：黄明强摘录日期：2007年5月3日是否好买估计：生产中心正在使用价格：概述：LM2596系列开关电压调节器是降压型电源管理单片集成电路，能够输出3A的驱动电流，同时具有很好的线性和负载调节特性。
固定输出版本有3.3V、5V、12V，还有一个输出可调版本。
添加少量的外部元件就可以使用该电压调节器。
该器件内部集成有频率补偿和固定频率发生器。
开关频率为150KHz，与低频开关调节器相比较，可以使用更小规格的滤波元件。
其封装形式包括标准的5脚TO-220封装和5脚TO-263表贴封装。
由于该器件可以使用通用的标准电感，这更优化了LM2596的使用，极大地简化了开关电源电路的设计。
该器件还有其他一些特点：在特定的输入电压和输出负载的条件下，输出电压的误差可以保证在±4%的范围内，振荡频率误差在±15%的范围内；可以用仅80μA的待机电流，实现外部断电；具有自我保护电路（一个两级降频限流保护和一个在异常情况下断电的过温完全保护电路）。
特征：※ 3.3V、5V、12V的固定电压输出和可调电压输出※可调输出电压范围1.2V～37V，±4%※封装形式：TO-220（T）和TO-263（S）※保证输出负载电流3A※输入电压可高达40V※仅需4个外接元件※很好的线性和负载调节特性※150KHz固定频率的内部振荡器※TTL关断能力※低功耗待机模式，I Q的典型值为80μA※高转换效率※使用容易购买的标准电感※具有过热保护和限流保护功能应用：※简易高效率降压调节器※在卡上的开关电压调节器※正到负电压转换器专利号：5382918典型电路（固定输出电压版本）：封装和型号：※弯曲交叉的引脚，通孔封装，5脚TO-220 (T)订货型号：LM2596T-3.3, LM2596T-5.0,LM2596T-12 or LM2596T-ADJ ※表面贴封装，5脚TO-263 (S)订货型号：LM2596S-3.3, LM2596S-5.0, LM2596S-12 or LM2596S-ADJ 极限条件：最大供电电压45VON /OFF 管脚输入电压-0.3≤V≤+25V反馈脚电压-0.3≤V≤+25V输出电压到地（稳态）-1V功率消耗内部限定储存温度-65°C 到+150°CESD易感性（人体模式）2KV焊接温度T封装(锡焊, 10秒) +260°C最大结温+150°C运行条件：温度范围－40°C≤T J≤+125°C供电电压 4.5V 到40VLM2596-3.3电参数说明：标准字体对应的项目适合于TJ=25℃时，粗体字对应的项目适合于全温度范围LM2596-5.0电参数说明：标准字体对应的项目适合于TJ=25℃时，粗体字对应的项目适合于全温度范围LM2596-12电参数所有输出电压版本电参数说明：标准字体对应的项目适合于TJ=25℃时，带下划线的粗斜体字对应的项目适合于整个温度范围。
lm2596-3.3 LM2596-ADJ LM2596-12 LV2596-3.3 中文资料
2.0
V(min)
5
μA
15
μA(max)
0.02
μA
5
μA(max)
注 2： 典型值是指在 25℃下的数值，代表最常见的情况。 注 3： 所有的极限参数都必须适合于室温（用正常字体表示）和极限温度（用带下划线的粗斜体字表示），所有室
温下的极限参数都是经过测试得出的，所有的极限温度下的极限参数都可以通过使用相关的标准静态质量控 制方法来加以保证。 注 4：二极管、电感、输入和输出端的电容以及调节输出电压的电阻等外接元件可能会影响开关调节器的系统性 能。当 LM2596 用在如图 1 所示测试电路中时，其系统性能如电气特性中系统参量所示。 注 5：当第二级电流极限功能启动时，开关频率会有所下降， 下降的程度取决于过电流的严重程度。 注 6：输出管脚不连接电感、电容或二极管。 注 7：把反馈管脚和输出管脚断开，把反馈管脚连到 0V，以强制输出开关晶体管导通。 注 8：把反馈管脚和输出管脚断开，把反馈管脚连到 12V（当 VOUT=3.3V、5V 或 ADJ 时）或 15V（当 VOUT=12V 时）， 以强制输出开关晶体管截止。 注 9：VIN=40V 注 10：环境热阻（不外加散热片）是指 TO-220 封装的 LM2596 垂直焊接在覆盖有面积约为 1 平方英寸铜箔的 PCB 上所对应的值。 注 11：TO-263 封装的 LM2596 垂直焊接在覆盖有面积约为 0.5 平方英寸铜箔的单面 PCB 上所对应的环境热阻。 注 12：TO-263 封装的 LM2596 垂直焊接在覆盖有面积约为 2.5 平方英寸铜箔的单面 PCB 上所对应的环境热阻。 注 13：TO-263 封装的 LM2596 垂直焊接在覆盖有面积约为 3 平方英寸铜箔的双面 PCB 上所对应的环境热阻，而 PCB 的另一面覆盖有面积约为 16 平方英寸铜箔。 注14： LM2596T-3.3, LM2596T-5.0, LM2596T-12， LM2596T-ADJ为TO-220封装（DIP）； LM2596S-3.3, LM2596S-5.0,LM2596S-12， LM2596S-ADJ为TO-263封装（SMT）。
LM2596T-15中文资料
元器件交易网3.0A, 150Khz, Step-Down Switching RegulatorFEATURES3.3V, 5.0V, 12V, 15V, and Adjustable Output Versions Adjustable Version Output Voltage Range, 1.23 to 37V +/- 4%. Maximum Over Line and Load Conditions Guaranteed 3.0A Output Current Wide Input Voltage Range Requires Only 4 External Components 150Khz Fixed Frequency Internal Oscillator TTL Shutdown Capability, Low Power Standby Mode High Efficiency Uses Readily Available Standard Inductors Thermal Shutdown and Current Limit Protection Moisture Sensitivity Level(MSL) Equals1 TO-263(D2) TO-220V TO-220LM2596ApplicationsSimple High-Efficiency Step-Down(Buck) Regulator Efficient Pre-Regulator for Linear Regulators On-Card Switching Regulators Positive to Negative Converter(Buck-Boost) Negative Step-Up Converters Power Supply for Battery Chargers1. 2. 3. 4. 5. Vin Output Ground Feedback On/OffDESCRIPTIONThe LM2596 series of regulators are monolithic integrated circuits ideally suited for easy and convenient design of a step-down switching regualtor(buck converter). All circuits of this series are capable of driving a 3.0A load with excellent line and load regulation. These devices are available in fixed output voltages of 3.3V, 5.0V,12V, 15V, and an adjustable output version.ORDERING INFORMATIONDevice LM2596T-X.X LM2596TV-X.X LM2596R Marking LM2596T-X.X LM2596T-X.X LM2596R-X.X Package TO-220 TO-220V TO-263These regulatiors were designed to minimize the number of externalcomponents to simplify the power supply design. Standard series of inductors optimized for use with the LM2576 are offered by several different inductor manufacturers. Since the LM2596 converter is a switch-mode power supply, its efficiency is significantly higher in comparison with popular three-terminal limear reguators, especially with higher input voltages. In many cases, the power dissipated is so low that no heatsink is required or its size could be reduced dramatically. A standard series of inductors optimized for use with the LM2596 are available from several different manufacturers. This feature greatly simplifies the design of switch-mode power supplies. The LM2596 features include a guaranteed +/- 4% tolerance on output voltage within specified input voltages and output load conditions, and +/-15% on the oscillator frequency (+/- 2% over 0oC to 125 oC). External shutdown is included, featuring 80 uA(typical) standby current. The output switch includes cycle-bycycle current limiting, as well as thermal shutdown for full protection under fault conditions.HTC1Oct 2004 - Rev 0元器件交易网3.0A, 15V, Step-Down Switching RegulatorTypical Application (Fixed Output Voltage Versions)LM2596LM2596-5.033 uH680 uF1N5824220 uFFigure 1. Block Diagram and Typical ApplicationABSOLUTE MAXIMUM RATINGS(Absolute Maximum Ratings indicate limits beyond which damage to the device may occur.)Power DissipationTO-220, 5-LeadThermal Resistance, Junction-to-Ambient Thermal Resistance, Junction-to-caseTO-263Thermal Resistance, Junction-to-Ambient Thermal Resistance, Junction-to-caseHTC2Oct 2004 - Rev 0元器件交易网3.0A, 15V, Step-Down Switching RegulatorLM2596OPERATING RATINGS (Operating Ratings indicate conditions for which the device is intended to befunctional, but do not guarantee specific performance limits. For guaranteed specifications and test conditions, see the Electrical Characteristics.)ELECTRICAL CHARACTERISTICS / SYSTEM PARAMETERS ([Note 1] Test Circuit Figure 2) (Unless otherwise specified, Vin = 12 V for the 3.3 V, 5.0 V, and Adjustable version, Vin = 25 V for the 12 V version, and Vin = 30 V for the 15 V version. ILoad = 500 mA. For typical values TJ = 25°C, for min/max values TJ is the operating junction temperature range that applies [Note 2], unless otherwise noted.)LM2596-3.3 ([ Note 1]. Test Circuit Figure 2 )73 LM2596-5.0 ([ Note 1]. Test Circuit Figure 2 ) 180 LM2596-12 ([ Note 1]. Test Circuit Figure 2 )90 LM2596-15 ([ Note 1]. Test Circuit Figure 2 )98 LM2596-ADJ ([ Note 1]. Test Circuit Figure 2 )73HTC3Oct 2004 - Rev 0元器件交易网3.0A, 15V, Step-Down Switching RegulatorELECTRICAL CHARACTERISTICS / Device ParametersLM2596(Unless otherwise specified, Vin = 12 V for the 3.3 V, 5.0 V, and Adjustable version, Vin = 25 V for the 12 V version, and Vin = 30 V for the 15 V version. ILoad = 500 mA. For typical values Tj = 25°C, for min/max values Tj is the operating junction temperature range that applies [Note 2], unless otherwise noted.)10 0 127 110 15050 100 173 1731.16 01.4 1.53.6 3.4100 4.5 6.9 7.5 50 30 1002 5 00 2 0 2.0 2.0 2 V LOGIC = 2.5V (Regulator OFF) V LOGIC = 0.5V (Regulator ON) 5 0.02 1.3 1.32500.6 0.6 15 5.001. External components such as the catch diode, inductor, input and output capacitors can affect switching regulator system performance. When the LM2596 is used as shown in the Figure 1 test circuit, system performance will be as shown in system parameters section . 2. Tested junction temperature range for the LM2596 : TLOW = –0°C THIGH = +125°C 3. The oscillator frequency reduces to approximately 18 kHz in the event of an output short or an overload which causes the regulated output voltage to drop approximately 40% from the nominal output voltage. This self protection feature lowers the average dissipation of the IC by lowering the minimum duty cycle from 5% down to approximately 2%. 4. Output (Pin 2) sourcing current. No diode, inductor or capacitor connected to output pin. 5. Feedback (Pin 4) removed from output and connected to 0 V. 6. Feedback (Pin 4) removed from output and connected to +12 V for the Adjustable, 3.3 V, and 5.0V ersions, and +25 V for the 12 V and15 V versions, to force the output transistor “off”. 7. Vin = 40 V.HTC4Oct 2004 - Rev 0元器件交易网3.0A, 15V, Step-Down Switching RegulatorTYPICAL PERFORMANCE CHARACTERISTICS (Circuit of Figure 2)LM2596HTC5Oct 2004 - Rev 0元器件交易网3.0A, 15V, Step-Down Switching RegulatorTYPICAL PERFORMANCE CHARACTERISTICS (Circuit of Figure 2)Feedback Pin Bias CurrentLM2596HTC6Oct 2004 - Rev 0元器件交易网3.0A, 15V, Step-Down Switching RegulatorTest Circuit and Layout GuidelinesLM2596Figure 2. Typical Test Circuits and Layout GuideAs in any switching regulator, layout is very important. Rapidly switching currents associated with wiring inductance can generate voltage transients which can cause problems. For minimal inductance and ground loops, the wires indicated by heavy lines should be wide printed circuit traces and should be kept as short as possible. For best results, external components should be located as close to the switcher lC as possible using ground plane construction or single point grounding. If open core inductors are used, special care must be taken as to the location and positioning of this type of inductor. Allowing the inductor flux to intersect sensitive feedback, lC groundpath and COUT wiring can cause problems. When using the adjustable version, special care must be taken as to the location of the feedback resistors and the associated wiring. Physically locate both resistors near the IC, and route the wiring away from the inductor, especially an open core type of inductor.HTC7Oct 2004 - Rev 0元器件交易网3.0A, 15V, Step-Down Switching RegulatorLM2596PIN FUNCTION DESCRIPTION Symbol 1VinDescription This pin is the positive input supply for the LM2596 step–down switching23 45regulator.In order to minimize voltage transients and to supply the switching currents needed by the regulator, a suitable input bypass capacitor must be present .(Cin in Figure 1). Output This is the emitter of the internal switch. The saturation voltage Vsat of this output switch is typically 1.5 V. It should be kept in mind that the PCB area connected to this pin should be kept to a minimum in order to minimize coupling to sensitive circuitry. Circuit ground pin. See the information about the printed circuit board layout. Gnd Feedback This pin senses regulated output voltage to complete the feedback loop. The signal is divided by the internal resistor divider network R2, R1 and applied to the non–inverting input of the internal error amplifier. In the Adjustable version of the LM2596 switching regulator this pin is the direct input of the error amplifier and the resistor network R2, R1 is connected externally to allow programming of the output voltage. ON/OFF It allows the switching regulator circuit to be shut down using logic level signals, thus dropping the total input supply current to approximately 80 mA. The threshold voltage is typically 1.4 V. Applying a voltage above this value (up to +Vin) shuts the regulator off. If the voltage applied to this pin is lower than 1.4V or if this pin is left open, the regulator will be in the "on" conditionHTC8Oct 2004 - Rev 0元器件交易网3.0A, 15V, Step-Down Switching RegulatorLM2596PACKAGES DIMENSION : TO220-5LHTC9Oct 2004 - Rev 0元器件交易网3.0A, 15V, Step-Down Switching RegulatorPACKAGES DIMENSION : TO220V-5LLM2596HTC10Oct 2004 - Rev 0元器件交易网3.0A, 15V, Step-Down Switching RegulatorLM2596PACKAGES DIMENSION : TO263-5LHTC11Oct 2004 - Rev 0。
LM2596芯片资料
150kHz, 3A PWM Buck DC/DC ConverterLM2596-XXE5/F5DescriptionThe LM2596-XXE5/F5 series of regulators are monolithic ICs that provide all active functions for a step-down (buck switching regulator, capable of driving 3A load with excellent line and load regulation. These devices are available in fixed output voltage of 3.3V, 5V, 12V and an adjustable output version. Requiring a minimum number of external components, these regulators are simple to use and include internal frequency compensation and a fixed- frequency oscillator.The LM2596-XXE5/F5 series operates at a switching frequency of 150kHz, thus allowing smaller sized filter components than what would be needed with lower frequency switching regulators. Available in standard 5-lead TO-220 and TO-263 packages with several different lead bend options. A standard series of inductors are available from several different manufacturers optimized for use with the LM2596-XXE5/F5 series. This feature greatly simplifies the design of switch-mode power supplies. Other features include a guaranteed ±4% tolerance on output voltage under specified input voltage and output load conditions, and ±15% on the oscillator frequency. External shutdown is included, featuring 80μA standby current. Self protection features include a two stage frequency reducing current limit for the output switch and an over temperature shutdown for complete protection under fault conditions.Features●3.3V, 5V, 12V, and adjustable output versions● Adjustable version output voltage range, 1.3V to 37V±4% max over line and load conditions● 150kHz±15% fixed switching frequency● TTL shutdown capability● Operating voltage can be up to 40V● Output load current:3A● TO220-5L and TO263-5L packages● Low power standby mode.● Thermal shutdown and current limit protection.● High efficiency● Built-in switching transistor on chip● Requires only 4 external components● Use readily available standard inductorsApplications● Simple high-efficiency step-down (buck regulator.● Positive to negative co nverter (Buck-Boost.● On-card switching regulators.Pin AssignmentBlock DiagramOrdering InformationAbsolute Maximum Ratings (Note 1Parameter Symbol Value UnitSupply V oltage V CC 45 V On/Off Pin Input V oltage V SD -0.3 ~ +25 V Feedback Pin V oltage V FB -0.3 ~ +25 V Output V oltage to Ground V OUT -1 V Power Dissipation P D Internally Limited W Operating Temperature Topr -40 ~ +125 ℃Storage Temperature Tstg -65 ~ +150 ℃ Operating V oltage V OP +4.5 ~ +40 VESD Susceptibility (Note 2 2000 VElectrical Characteristics (All Output Voltage VersionsSpecifications with boldface type are for full operating temperature range, the other type are for T J =25°C.(Unless otherwise specified, V IN =12V for the 3.3V , 5V , and adjustable version and V IN =24V for the 12V version, I LOAD =500mAParameter Symbol Test Condition Min Typ Max UnitDevice parameters50Feedback Bias CurrentIbAdjustable Version Only, V FB = 1.3V- 10 100nA127 173Oscillator Frequency f O (Note 6110 150 173KHz 1.4Saturation V oltage V SAT I OUT =3A (Note 7, 8 - 1.16 1.5 V Max Duty Cycle (ON100 Min Duty Cycle(OFF DC (Note 8(Note 9 - 0- % 3.6 6.9Current LimitI CL Peak Current ( Note 7, 83.44.5 7.5A Output=0V (Note 7, 9 - - 50 μA Output Leakage Current I LOutput=-1V (Note 10 - 2 30 mA Quiescent Current I Q (Note 9 - 5 10 mA200Standby Quiescent CurrentI STBY ON/OFF pin=5V (Note 10 - 80 250μATO-220-5L - 2 - θJC TO-263-5L Junction to Case- 3.5 - /W℃TO-220-5L- 50 - Thermal Resistance θJA (Note11 TO-263-5L Junction to Ambient - 23 -/W ℃ON/OFF ControlV IH Low (Regulator ON - 0.6 ON/OFF Pin Logic Input Threshold Voltage V IL High (Regulator OFF2.0 1.3 - V I IH V LOGIC =2.5V (Regulator OFF - 5 15 ON/OFF Pin Input CurrentI ILV LOGIC =0.5V (Regulator ON-0.025μAElectrical Characteristics (ContinuedSpecifications with boldface type are for full operating temperature range, the other type are for T J=25°C.Part No. Parameter Symbol Conditions Min Typ(Note 3Max (Note 4UnitsOutput V oltage V OUT 4.75V≤V IN≤40V, 0.2A≤I LOAD≤3A 3.1683.1353.33.4323.465VLM2596-3.3Efficiency ηV IN=12V, I LOAD=3A - 73 - %Output V oltage V OUT7V≤V IN≤40V, 0.2A≤I LOAD≤3A 4.8004.7505.05.2005.250VLM2596-5.0Efficiency ηV IN=12V, I LOAD=3A - 80 - %Output V oltage V OUT15V≤V IN≤40V, 0.2A≤I LOAD≤3A 11.5211.4012.012.4812.60VLM2596-12Efficiency ηV IN=25V, I LOAD=3A - 90 - %Output Feedback V FB4.5V≤V IN≤40V, 0.2A≤I LOAD≤3AV OUT programmed for 3V1.1801.1681.2301.2801.292VLM2596-ADJEfficiency ηV IN=12V, V OUT=3V, I LOAD=3A - 77 - % Note 1 :Absolute Maximum Ratings indicate limits beyond which damage to the device may occur. Operating Ratings indicate conditions for which the device is intended to be functional, but do not guarantee specific performance limits. Forguaranteed specifications and test conditions, see the Electrical Characteristics.Note 2 : The human body model is a 100pF capacitor discharged through a 1.5K resistor into each pin.Note 3 : Typical numbers are at 25℃ and represent the most likely norm.Note 4 : All limits guaranteed at room temperature (standard face type and at temperature extremes(bold face type. All room temperature limits are 100% production tested. All limits at temperature extremes are guaranteed via correlation usingstandard Statistical Quality Control (SQC methods. All limits are used to calculate Average Outgoing Quality Level(AOQL.Note 5 : External components such as the catch diode, inductor, input and output capacitors, and voltage programming resistors can affect switching regulator system performance.Note 6 : The switching frequency is reduced when the second stage current limit is activated.Note 7 : No diode, inductor or capacitor connected to output pin.Note 8 : Feedback pin removed from output and connected to 0V to force the output transistor switch ON.Note 9 : Feedback pin removed from output and connected to +12V for the 3.3V, 5V and adjustable version, and +15V for the 12V version, to force the output transistor switch OFF.Note 10 : V IN=40V.Note 11 : Junction to Ambient thermal resistance. (With copper area of approximately 3 in²Typical Performance Characteristics (circuit of Figure 2Typical Performance Characteristics(Cont.Typical Performance Characteristics(Cont.Typical Performance Characteristics(Cont.Typical Application CircuitTO-263-5L DimensionInches Millimeters Inches Millimeters LM2596□□□ □□□□Date CodeDIMMin. Max. Min. Max. DIMMin. Max. Min. Max.A 0.173 0.189 4.40 4.80 L5 0.244 0.260 6.20 6.60 b 0.030 0.039 0.76 1.00 c1 0.0490.057 1.25 1.45 c 0.014 0.020 0.36 0.50 L 0.522 0.561 13.25 14.25 D 0.339 0.354 8.60 9.00 e 0.067 REF 1.70 REF E 0.386 0.409 9.80 10.4 L1 0.102 0.114 2.60 2.89 L4 0.579 0.602 14.7 15.3 φ 0.146 0.156 3.71 3.96Notes: 1.Controlling dimension: millimeter2.Maximum lead thickness includes lead finish thickness, and minimum lead thickness is the minimum thickness of base material.3.If there is any question with packing specification or packing method, please contact your local CYStek sales office.Material:• Mold Compound: Epoxy resin family, flammability solid burning class: UL94V-0CYStech Electronics Corp. TO-263-5L Dimension Spec. No. : C548F5 Issued Date : 2007.12.11 Revised Date : Page No. : 11/12 Marking: LM2596□□□ Date Code □□□□ Vout: 3.3V→-33 5.0V→-50 12V→-12 ADJ→ blank Style: Pin 1.Vin 2.Vout 3.GND4.Feedback5.ON/OFF 5-Lead TO-263-5L Plastic Package CYStek Package Code: F5 DIM A b L4 c L1 E Inches Min. Max. 0.173 0.189 0.026 0.036 0.000 0.012 0.014 0.020 0.090 0.110 0.386 0.409 Millimeters Min. Max. 4.40 4.80 0.66 0.91 0.00 0.30 0.36 0.50 2.29 2.79 9.80 10.4 DIM c2 L2 D e L θ Inches Min. Max. 0.049 0.057 0.050 REF 0.3390.354 0.067 REF 0.575 0.622 0° 8° Millimeters Min. Max. 1.25 1.45 1.27 REF 8.60 9.001.70 REF 14.6 15.8 0° 8° Notes: 1.Controlling dimension :millimeter2.Maximum lead thickness includes lead finish thickness, and minimum lead thickness is the minimum thickness of base material.3.If there is any question with packing specification or packing method, please contact your loca l CYStek sales office. Material: • Mold Compound: Epoxy resin family, flammability solid burning class: UL94V-0 Recommended wave soldering condition Product Pb-free devices LM2596-XXE5/F5Peak Temperature 260 +0/-5 °C Soldering Time 5 +1/-1 seconds CYStek Product SpecificationCYStech Electronics Corp. Recommended temperature profile for IR reflow Spec. No. : C548F5 Issued Date : 2007.12.11 Revised Date : Page No. : 12/12 Profile feature Average ramp-up rate (Tsmax to Tp Preheat −Temperature Min(TS min −Te mperature Max(TS max −Time(ts min to ts max Time maintained above: −Temperature (TL − Time (tL Peak Temperature(TP Time within 5°C of actual peak temperature(tp Ramp down rate Time 25 °C to peak temperature Sn-Pb eutectic Assembly 3°C/second max. 100°C 150°C 60-120 seconds 183°C 60-150 seconds 240 +0/-5 °C 10-30 seconds 6°C/second max. 6 minutes max. Pb-free Assembly 3°C/second max. 150°C 200°C 60-180 seconds 217°C 60-150 seconds 260 +0/-5 °C 20-40 seconds 6°C/second max. 8 minutes max. Note : All temperatures refer to topside of the package, measured on the package body surface. Important Notice: • All rights are reserved. Reproduction in whole or in part is prohibited without the prior written approval of CYStek. • CYStek reserves the right to make changes to its products without notice. • CYStek semiconductor products are not warranted to be suitable for use in Life-Support Applications, or systems. • CYStek assumes no liability for any consequence of customer product design, infringement of patents, or application assistance. LM2596-XXE5/F5 CYStek Product Specification。
G5ULM2596资料
G 5U L M 2596Simple Switcher Power converter 150kHz 3A Step-Down Voltage Regulator DescriptionThe G5ULM2596 series of regulators are monolithic integrated circuits that provide all active functions for a step-down (buck) switching regulator, capable of driving 3A load with excellent line and load regulation. These devices are available in fixed output voltage of 3.3v, 5v, 12v and an adjustable output version. Requiring a minimum number of external components, these regulators are simple to use and include internal frequency compensation and a fixed-frequency oscillator.The G5ULM2596 series operates at a switching frequency of 150 kHz thus allowing smaller sized filter components than what would be needed with lower frequency switching regulators. Available in a standard 5-lead TO-263 package with several different lead bend options. A standard series if inductors are available from several different manufactures optimized for use with the G5ULM2596 series. This feature greatly simplifies the design of switch-mode power supplies. Other feature include a guaranteed ±4% to tolerance on output voltage under specified input voltages and output load conditions, and ±15% on the oscillator frequency. External shutdown is included, featuring 80uA standby current. Self protection features include a two stage frequency reducing current limit for the output switch and an over temperature shutdown for complete protection under fault conditions.Features3.3V, 5.0V, 12V and adjustable output versionsAdjustable version output voltage range , 1.2V to 37V ±4% max over line and load conditions Guaranteed 3A output current Input voltage range up to 40VEfficient pre-regulator for linear regulators Requires only 4 external components 150kHz fixed frequency internal oscillatorTTL shutdown capability, low power standby mode High efficiencyUses readily available standard inductorsThermal shutdown and current limit protectionApplicationsSimple high-efficiency step-down (buck) regulator On-card switching regulators Positive to negative converterPackage DimensionsMillimeterMillimeterREF . Min. Max. REF .Min.Max. A 4.40 4.80 c2 1.25 1.45 b 0.66 0.91 L2 1.27 REF . L4 0.00 0.30 B D 8.6 9.0 c 0.36 0.5 e 1.70 REF . L1 2.29 2.79 L 14.6 15.8 E9.80 10.40˚ 8˚Typical Application (Fixed Output Voltage Version)G5ULM2596-5.0 12VUnregulated DC Input68033 2201N5824680Block DiagramOperating RatingsParameterRatings Unit Temperature range -40 T J +125 Supply Voltage4.5 ~ 40VG5ULM2596-3.3 Electrical CharacteristicsSpecifications with standard type face are for T J=25 , and those with boldface type apply over full operating temperature rangeParameter Symbol Conditions Min(Note4)Typ(Note3)Max(Note4)UnitSystem Parameters (Note5) Test Circuit Figure 2Output Voltage V OUT 4.75V V IN 40V0.2A I LOAD 3A 3.168/3.135 3.3 3.432/3.465V Efficiency V IN=12V, I LOAD=3A 73 % G5ULM2596-5.0 Electrical CharacteristicsSpecifications with standard type face are for T J=25 , and those with boldface type apply over full operating temperature rangeParameter Symbol Conditions Min(Note4)Typ(Note3)Max(Note4)UnitSystem Parameters (Note5) Test Circuit Figure 2Output Voltage V OUT7V V IN 40V0.2A I LOAD 3A 4.80/4.75 5.0 5.20/5.25V Efficiency V IN=12V, I LOAD=3A 80 % G5ULM2596-12 Electrical CharacteristicsSpecifications with standard type face are for T J=25 , and those with boldface type apply over full operating temperature rangeParameter Symbol Conditions Min(Note4)Typ(Note3)Max(Note4)UnitSystem Parameters (Note5) Test Circuit Figure 2Output Voltage V OUT15V V IN 40V0.2A I LOAD 3A 11.52/11.4012 12.48/12.60V Efficiency V IN=15V, I LOAD=3A 90 % G5ULM2596 Electrical CharacteristicsSpecifications with standard type face are for T J=25 , and those with boldface type apply over full operating temperature rangeParameter Symbol Conditions Min(Note4)Typ(Note3)Max(Note4)UnitSystem Parameters (Note5) Test Circuit Figure 2Output Voltage V OUT 4.5 V IN 40V,0.2A I LOAD 3AV OUT=3V, Circuit of Figure 21.180/1.168 1.230 1.280/1.292V Efficiency V IN=12V, I LOAD=3A, V OUT=3V 77 % All Output Voltage Version Electrical CharacteristicsSpecifications with standard type face are for T J=25 , and those with boldface type apply over full operating temperature range.Note 1: Absolute Maximum Rating indicate limits beyond which damage to the device may occur. Operating Rating indicate conditions for which the device is intended to be functional, but do not guaranteed specific performance limits. For guaranteed specifications and test conditions, see the Electrical Characteristics.Note 2: The human body mode is a 100pF capacitor discharged through a 1.5k resistor into each pin.Note 3: Typical number are at 25 and represent the most likely norm.Note 4: All limits guaranteed at room temperature (standard type face) and at temperature extremes (bold type face). All room temperature limits are 100% production tested. All limits at temperature extremes are guaranteed via correlation using standard Statistical Quality Control (SQC) method. All limits are used to calculate Average Outgoing Quality Level (AOQL).Note 5: External component such as the catch diode, inductor, input and output capacitors, and voltage programming resistor can affect switching regulator system performance. When the G5ULM2596 is used as shutdown in the Figure 1 test circuit, system performance will be as shown in system parameters section of Electrical Characteristics.Note 6: The switching frequency is reduced when the second stage current limit is activated. The amount of reduction is determined by the severity of current over-load.Note 7: No diode, inductor or capacitor connected to output pin.Note 8: Feedback pin removed from output and connected to 0V to force the output transistor switch ON.Note 9: Feedback pin removed from output and connected to 12V for the Adjustable, 3.3V and 5V versions, and 15V for the 12V version, to force the output transistor switch OFF.Note 10: V IN=40V.Note 11: Junction to ambient thermal resistance with the TO -263 package tab soldered to a single sided printed circuit board with 0.5 in2 of (1 oz.) copper area.Note 12: Junction to ambient thermal resistance with the TO -263 package tab soldered to a single sided printed circuit board with 2.5 in2 of (1 oz.) copper area.Note 13: Junction to ambient thermal resistance with the TO -263 package tab soldered to a double sided printed circuit board with 3.0 in2 of (1 oz.) copper area on the G5ULM2596 side of the board, and approximately 16in2 of copper on the other side of the p-c board. Typical Performance Characteristics (circuit of Figure 2)Efficiency Switch Saturation VoltageSwitch Current Limit Dropout VoltageOperating Quiescent CurrentShutdown Quiescent CurrentMinimum Operating Supply Voltage ON/OFF Threshold VoltageON/OFF Pin Current (Sinking) Switching FrequencyFeedback Pin Bias CurrentContinuous Mode Switching Waveforms Horizontal Time Base: 2 s /div Discontinuous Mode Switching WaveformsHorizontal Time Base: 2 s /divLoad Transient Response for Continuous Mode Horizontal Time Base: 100 s /div Horizontal Time Base: 200 s /divLoad Transient Response for Discontinuous ModeTest Circuit and layout GuidelinesAs in any switching regulator, layout is very important. Rapidly switching currents associated with wiring inductance generate voltage transients which can cause problems. For minimal inductance and ground loops, the wires indicated by heavy lines should be wide printed circuit traces and should be kept as short as possible. For best results, external components should be located as close to the switcher IC as possible using ground plane construction or single point grounding.If open core inductors are used, special care must be taken as to the location and positioning of this type of inductor. Allowing the inductor flux to intersect sensitive feedback, IC groundpath and C OUT wiring can cause problems. When using the Adjustable version, special care must be taken as to the location of the feedback resistors and the associated wiring. Physically locate both resistors near the IC, and route the wiring away from the inductor, especially an open core type of inductor.Vout=VREF*(1+R2/R1) Where VREF=1.23V R2=R1*(Vout/VREF-1)Select R1 to be approximately 1k , use a 1% resistor for best stability. Cin-- 470uF, 50V , Aluminum Electrolytic Cout-- 220uF, 35V Aluminum Electrolytic D1-- 5A, 40V Schottky Rectifer, 1N5825 L1-- 68uHFigure 2 Standard Test Circuits and Layout GuidesCin-- 470uF, 50V , Aluminum Electrolytic Cout-- 220uF, 25V Aluminum Electrolytic D1-- 5A, 40V Schottky Rectifer, 1N5825 L1-- 68uH。
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ON/OFF 脚逻辑输入
VIH
门槛电压
VIL
低（调节器开） 高（调节器关）
IH
ON/OFF 脚输入电流 IL
VLOGIC=2.5V（调节器关） VLOGIC=0.5V（调节器开）
LM2596□—XX
典型值（2） 极限值（3）
单位
2
℃/W
50
℃/W
50
℃/W
30
℃/W
20
℃/W
1.3
V
0.6
V(max)
由内部限定
储存温度
-65～150
静电释放（人体放电 1）
2000
气流焊（60 秒）
215
焊接时的管脚
TO-263
红外线焊接（10 秒）
245
温度
TO-220
波峰焊/电烙铁焊接（10 秒）
260
最高结温
150
工 作条 件
温度范围 电源电压
-40～125 4.5～40
注 1：人体放电模式相当于一个 100PF 的电容通过一个 1.5K 的电阻向每个管脚放电。
电气特性
单位 V V V V -℃ V ℃ ℃ ℃ ℃ ℃ V
说明：标准字体对应的项目适合于 TJ=25℃时，带下划线的粗斜体字对应的项目适合于整个温度范围； 系统参量(4) 测试电路见图 1
符号
参量
条件
典型值（2）
极限值（3）
单位
LM2596□—3.3 （见注 14）
VOUT
输出电压
3.3 4.75V≤VIN≤40V，
应用领域
※ 高效率降压调节器 ※ 单片开关电压调节器 ※ 正、负电压转换器
典型应用（固定输出）
LM2596□-5.0
１
管脚图
LM2596 开关电压调节器 SEPTEMBER， 2004
极限参数
名称
范围
最大电源电压
45
脚输入电压
-0.3～25
“反馈”脚电压
-0.3～25
到地的输出电压（静态）
-1
功耗
V V（min） V（max） %
1.193/1.180 1.267/1.280
V V（min） V（max）
% %
说明：标准字体对应的项目适合于 TJ=25℃时，带下划线的粗斜体字对应的项目适合于整个温度范围。除非特别说 明，VIN=12V 对应于 LM2596□ —3.3、 LM2596□ —5.0、LM2596□ —ADJ，VIN=24V 对应于 LM2596□ —12. ILOAD=500mA。 （见注 14）
4.800/4.750 5.200/5.250
V V（min） V（max） %
２
LM2596 开关电压调节器 SEPTEMBER， 2004
符号
参量
条件
LM2596□—12 （见注 14）
VOUT
输出电压
15V≤VIN≤40V， 0.2A≤ILOAD≤3A
η
效率
VIN=25V，ILOAD=3A
LM2596□—ADJ （见注 14）
4.5V≤VIN≤40V，
VFB
反馈电压
0.2A≤ILOAD≤3A
VOUT 调为 3V， 电路图见图 1
η
效率
VIN=25V，VOUT =3V， ILOAD=3A
VIN=25V，VOUT =15V，ILOAD=3A
电气特性（所有输出）
典型值（2） 极限值（3）
单位
12.0
88 1.230
73 90
11.52/11.40 12.48/12.60
特点
※ 3.3V、5V、12V 的固定电压输出和可调电压输出 ※ 可调输出电压范围 1.2V～37V±4% ※ 输出线性好且负载可调节 ※ 输出电流可高达 3A ※ 输入电压可高达 40V ※ 采用 150KHz 的内部振荡频率，属于第二代开关电压调节器，功耗小、效率高 ※ 低功耗待机模式，IQ 的典型值为 80μA ※ TTL 断电能力 ※ 具有过热保护和限流保护功能 ※ 封装形式：TO-220（T）和 TO-263（S） ※ 外围电路简单，仅需 4 个外接元件， 且使用容易购买的标准电感
见注 9 ON/OFF 脚=5V（OFF）（9）
LM2596□—XX
典型值（2） 极限值（3）
单位
10
nA
50/100 150
nA(max) KHz
127/110
KHz(min)
173/173
KHz(max)
1.16
V
1.4/1.5
V(max)
100
%
0
%
4.5
A
3.6/3.4
A(min)
6.9/7.5 50
ESR）钽电容值在 10μF 到 470μF 之间效果最好。电容应该靠近 IC，同时，电容的管脚要短，连接的铜线也 要短，电容值不要大于 820μF。 B. 为了简化电容选择步骤，请参阅表 2 所示的电容快速选择，这个表包含了最好的设计方案所需的不同的输入电 压、输出电压、负载电流、不同的电感和输出电容。 C. 电解电容的耐压至少应是输出电压的 1.5 倍，为了得到纹波更低的输出电压，需要更高耐压值的电容器。 3. 吸纳二极管的选择（D1） A. 吸纳二极管的最大承受电流能力至少要为最大负载电流的 1.3 倍，如果设计的电源要承受连续的短路输出，则 吸纳二极管的最大承受电流能力要等于 LM2596 的极限输出电流。对吸纳二极管来说，最坏的情况是过载或输 出短路。 B. 吸纳二极管的反向耐压至少要为 最大输入电压的 1.25 倍。 C. 吸纳二极管必须是快恢复的且必须靠近 LM2596，此二极管的管脚要短，连接的铜线也要短。由于所需的二极 管开关速度快、正向压降低，所以，肖特基二极管是首选，同时，它的性能和效率都很好，特别是在低输出电 压情况下更是如此。使用超快恢复或高效整流二极管效果也很好。超快恢复二极管的典型恢复时间为 50ns 或更 快，象 IN5400 系列的整流二极管速度很慢，通常不用。 4. 输入电容的选择（CIN） 为了防止在输入端出现大的瞬态电压，在输入端和地之间要加一个低等效电阻的铝或钽电容作为旁路电容，这 个电容要靠近 IC。另外，输入电容电流的均方根值至少要为直流负载电流的一半。要确保所选的电容的这个参数不 能低于直流负载电流的一半。几个不同的铝电解电容的典型均方根电流值所对应的曲线如图 13 所示。对铝电解电 容，其耐压值要为最大输入电压的 1.5 倍。必须注意的是，如果使用了钽电容，则它的耐压要为输入电压的 2 倍， 推荐使用生产厂家测试过浪涌电流的电容。使用瓷片电容为输入旁路电容时要特别小心，因为这可能会在输入脚处 引起非常严重的噪声。
５
LM2596 开关电压调节器 SEPTEMBER， 2004
TO-263 封装（S）尺寸图
单位：英寸/毫米
TO-220 封装（T）尺寸图
单位：英寸/毫米
６
LM2596 开关电压调节器 SEPTEMBER， 2004
设计步骤及实例
固定输出调节器的设计步骤
条件：VOUT=3.3（或 5 、或 12）V , VIN（max）为最大直流输入电压, ILOAD（max）为最大负载电流 步骤： 1. 电感的选择（L1） A． 要根据图 4、图 5 和图 6 所示的数据选择电感的适当值（分别对应输出电压为 3.3V、5V 和 12V），对于所有的
LM2596 开关电压调节器 SEPTEMBER， 2004
LM2596 开关电压调节器
LM2596 开关电压调节器是降压型电源管理单片集成电路，能够输出 3A 的驱动电流，同时具有很好的线性和 负载调节特性。固定输出版本有 3.3V、5V、12V， 可调版本可以输出小于 37V 的各种电压。
该器件内部集成频率补偿和固定频率发生器，开关频率为 150KHz，与低频开关调节器相比较，可以使用更小 规格的滤波元件。由于该器件只需 4 个外接元件，可以使用通用的标准电感，这更优化了 LM2596 的使用，极大地 简化了开关电源电路的设计。
符号
参量
器件参数
Ib
反馈偏置电流
fO
振荡器频率
VSAT
饱和电压
最大工作周期（ON） DC
最小工作周期(OFF）
ICL
极限电流
IL
输出漏电流
IQ ISTBY
静电流 待机静电流
条件
只适用于输出可调节的情况，VFB=1.3V
见注 5
IOUT=3A（6,7） 见注 7 见注 8
峰值电流（6，7） 输出为 0V（6，8） 输出为-1V（9）
纹波滤波电路
注：反馈线要远离电感，电路中的粗线一定要短，最好用地线屏蔽，调节输出电压的电阻 R1、R2 要靠近 LM2596 的 4 脚。
输出电压的计算可由下式给出：
， 其中 VREF=1.23V，
，为了确保输出稳定， R1 选用标称阻值为 1KΩ，精度为 1%的电阻。
CIN---470μF/50V COUT----220μF/35V
其他输出电压的情况，请看输出可调的调节器的设计步骤。 B． 在图 4、图 5 和图 6 上，由最大输入电压线和最大负载电流线的交叉区域确定电感的值，每一个区域都对应一
个电感值和一个电感代号（LXX）。 C． 从图 8 中所列的 4 个厂家所列的产品号中选择一个合适的电感，最好使用磁屏蔽结构的电感器。 2. 输出电容的选择（COUT） A. 在大多数的应用中，低等效电阻（Low ESR）的电解电容值在 82μF 到 820μF 之间，而低等效电阻（Low
４Hale Waihona Puke 测试电路及其布线方案（固定输出）
LM2596 开关电压调节器 SEPTEMBER， 2004
注：反馈线要远离电感，电路中的粗线一定要短，最好用 地线屏蔽。