LTC3127中文资料

PROG Voltage................................................. –0.3 to 6V Operating Junction Temperature Range ....................................................–40°C to 85°C (Note 2). Maximum Junction Temperature (Note 5)............ 125°C Storage Temperature Range................... –65°C to 125°C
3127f

LTC3127 Absolute Maximum Ratings
(Note 1)
VIN , VOUT Voltage .......................................... –0.3 to 6V SW1, SW2 DC Voltage.................................... –0.3 to 6V SW1, SW2 Pulsed (<100ns) Voltage............... –0.3 to 7V MODE, FB, VC Voltage..................................... –0.3 to 6V SHDN Voltage ................................................ –0.3 to 6V
90 VOUT 3.3V 1A LOAD 80
OFF ON 10µF
2.2mF 182k
70 60
L1: COILCRAFT XPL4020-472ML
50 2.5
VOUT = 3.3V L = 4.7µH F = 1.35MHz 3 3.5 4 VIN(V) 4.5 5 5.5
3127 TA01a
Features
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LTC3127 1A Buck-Boost DC/DC Converter with Programmable Input Current Limit Description
The LTC®3127 is a wide VIN range, highly efficient, 1.35MHz fixed frequency buck-boost DC/DC converter that operates from input voltages above, below or equal to the output voltage. The LTC3127 features programmable average input current limit, making it ideal for power-limited input sources. The input current limit is programmed with a single resistor and is accurate from 0.2A to 1A of average input current. The topology incorporated provides a continuous transfer function through all operating modes. Other features include <1μA shutdown current, pin-selectable Burst Mode operation and thermal overload protection. The LTC3127 is housed in thermally enhanced 10-lead (3mm × 3mm × 0.75mm) DFN packages and 12-lead MSOP packages.
3trical Characteristics
PARAMETER Input Operating Range Output Voltage Adjust Feedback Voltage Feedback Input Current Quiescent Current—Burst Mode Operation Quiescent Current—Shutdown Quiescent Current—Active Input Current Limit VFB = 1.25V VFB > 1.225, VMODE = VIN (Note 4) VSHDN = 0V, Including SW Leakage VFB > 1.225V, VMODE = 0V (Note 4) RPROG = 32.4k (Note 3) 0°C to 85°C (Note 3) –40°C to 85°C (Note 3) Peak Current Limit Reverse-Current Limit P-Channel MOSFET Leakage N-Channel MOSFET On-Resistance P-Channel MOSFET On-Resistance Maximum Duty Cycle Minimum Duty Cycle Frequency Accuracy SHDN Input High Voltage SHDN Input Low Voltage SHDN Input Current MODE Input High Voltage MODE Input Low Voltage MODE Input Current VMODE = 5.5V VSHDN = 5.5V
Applications
n n n
n n
USB Powered GSM Modems Supercap Charger Handheld Test Instruments PC Card Modems Wireless Terminals
Typical Application
USB or Li-Ion (500mA Maximum Input Current) to 3.3V
Pin Configuration
TOP VIEW SW1 VIN SHDN MODE PROG 1 2 3 4 5 11 PGND 10 SW2 9 VOUT 8 VC 7 FB 6 SGND PGND SW1 VIN SHDN MODE PROG 1 2 3 4 5 6 TOP VIEW 12 11 10 9 8 7 PGND SW2 VOUT VC FB SGND
l l l l l
The l denotes the specifications which apply over the full operating temperature range, otherwise specifications are at TJ = 25°C. VIN = 3.6V, VOUT = 3.3V, unless otherwise noted.
Consult LTC Marketing for parts specified with wider operating temperature ranges. Consult LTC Marketing for information on non-standard lead based finish parts. For more information on lead free part marking, go to: /leadfree/ For more information on tape and reel specifications, go to: /tapeandreel/
13 PGND
DD PACKAGE 10-LEAD (3mm s 3mm) PLASTIC DFN TJMAX = 125°C, θJA = 43°C/W (NOTE 6) EXPOSED PAD (PIN 11) IS PGND, MUST BE SOLDERED TO PCB
MSE PACKAGE 12-LEAD PLASTIC MSOP TJMAX = 125°C, θJA = 40°C/W (NOTE 6) EXPOSED PAD (PIN 11) IS PGND, MUST BE SOLDERED TO PCB
500 500 500 2.5 0.3 0.1 140 170 160 190
order information
LEAD FREE FINISH LTC3127EDD#PBF LTC3127EMSE#PBF TAPE AND REEL LTC3127EDD#TRPBF LTC3127EMSE#TRPBF PART MARKING LDYD 3127 PACKAGE DESCRIPTION 10-Lead (3mm × 3mm) Plastic DFN 12-Lead Plastic MSOP TEMPERATURE RANGE –40°C to 85°C –40°C to 85°C
Programmable (0.2A to 1A) ±4% Accurate Average Input Current Limit n Regulated Output with Input Voltages Above, Below or Equal to the Output n 1.8V to 5.5V (Input) and 1.8V to 5.25V (Output) Voltage Range n 0.6A Continuous Output Current: V > 1.8V IN n 1A Continuous Output Current: V > 3V IN n Single Inductor n Synchronous Rectification: Up to 96% Efficiency n Burst Mode® Operation: I = 35μA (Pin Selectable) Q n Output Disconnect in Shutdown n <1μA Shutdown Current n Small, Thermally Enhanced 10-Lead (3mm × 3mm × 0.75mm) DFN and 12-Lead MSOP Packages
L, LT, LTC, LTM, Linear Technology, Burst Mode and the Linear logo are registered trademarks and PowerPath and ThinSOT are trademarks of Linear Technology Corporation. All other trademarks are the property of their respective owners.
L1 4.7µH SW1 VIN MODE SHDN FB VC PROG SGND PGND 32.4k 100pF 499k
3127 TA01
Efficiency vs VIN
100 300mA LOAD
EFFICIENCY (%)
USB OR Li-Ion 2.9V to 5.5V
SW2 VOUT 320k
CONDITIONS
l l l
MIN 1.8 1.8 1.165
TYP
MAX 5.5 5.25
UNITS V V V nA µA µA µA mA mA mA A A µA mΩ mΩ mΩ mΩ % %
1.195 1 35 0.1 400
1.225 50 4 520 540 540 0.45 4
480 465 430 2 0.15