毕业设计文献翻译完美版

《毕业设计》
文献翻译
院系：电子电气工程学院学号：021309208
姓名：吴骁奕
指导教师：曾国辉
完成时间：2013/2/15
文献翻译
021309208 吴骁奕
A Flexible LED Driver for Automotive Lighting Applications: IC Design and E xperimental Characterization
一个灵活的LED驱动汽车照明应用:集成电路设计和实验特征
Abstract—This letter presents a smart driver for LEDs, particularly
摘要：这文章提出了一个智能驱动发光二极管，
for automotive lighting applications, which avoid ringing
尤其是用于避免振荡和超调现象的汽车照明应用上，
and overshoot phenomena. To this aim, advanced Soft Start and
为了这个目的，在芯片上集成了优化软启动和电流升降控制技术。

Current Slope Control techniques are integrated on-chip. This letter
这篇文章讨论了设计于集合于高电压的互补金属氧化半导体上的驱动技术，
discusses the driver design integrating in high voltage CMOS
technology, the digital circuitry for programming and electronic
用于编程和电子控制单元连接的数字电路以及功率元件提高到10瓦特。

control units interfacing, and the power devices up to 10W. Experimental
同时也展示了不同功率等级使用的发光二极管和与不同类型的连接时的实验特征。

characterizations with LEDs of different power levels and
with different types of connections are showed. The smart driver
这个智能的驱动适用于可调节的温度和电压需求。

sustains automotive temperature and voltage requirements; moreover
此外，它有很高的功率效率，它是可编程的，还可以配置用于线性的调节器。

it has high power efficiency, it is programmable, and can be
configured to work as a linear regulator (for low current LEDs) or
in switch mode (for higher power LEDs).
（用于弱电流发光二极管）或转换模式（用于高功率发光二极管）IndexTerms—Automotive electronics, high voltage (HV)CMOS,
integrated circuit (IC), LED driver.
关键词—汽车用电子设备，高电压互补金属氧化物半导体，集成电路
LED驱动
I. INTRODUCTION
1：介绍
IN the last few years LED technology experienced a very fast
在过去的几年中，发光二极管技术在汽车照明应用中替代普通灯泡经历了一个非常快速的进步时代，
and important growth, superseding the bulb technology in
automotive lighting applications [1]. To achieve the harsh requirement
of CO2 emission and reduce the fuel consumption,
car manufacturer must reduce the total power consumption. The
为了实现了严格的二氧化碳排放要求和降低了燃料的消耗,
汽车制造商必须减少总的功率消耗。

adoption of LEDs in place of bulbs permits to have about five
times less power consumption at equal output lighting intensity.
采用发光二极管代替灯泡在同等输出功率照明强度下损耗将降低五倍。

LEDs have reached quality and reliability factors that permit
their use in automotive harsh environment and in addition
发光二极管已达到质量和可靠性因素,可保证他们可使用在汽车的严
酷环境下并且他们的成本是降低的。

their cost is decreasing. However, LEDs are pretty difficult to
事实上，发光二极管是很难驱动，因此相比较普通灯泡，发光二极管驱动要求更多的技巧和控制功能。

drive and therefore LED-drivers require many tricks and control
functions compared to bulb drivers. Moreover, automotive
而且，汽车应用程序需要紧凑和低成本的解决方案,灵活
足够的数字电子控制单元界面，
applications require compact and low-cost solutions, flexible
enough to be interfaced to digital electronic control units (ECU)
and to cope with different wiring configurations and relevant
同时需要应付不同的布线配置和相关拓展。

parasitics [2]. Automotive lighting systems should be also robust
汽车照明系统也应该对电磁干扰(EMI)和超温、过流以及过电压现象有应变能力。

with respect to electromagnetic interference (EMI) and
to overtemperature, overcurrent, and overvoltage phenomena,
such as those due to ringing effects generated by resonance of
例如那些由于激振效应所产生的共振的线电感和连接器电容。

wire inductance and connector capacitance. Usually, in car environment
通常,在汽车环境中，几米长电线使用,就会生成强烈振荡。

few meters long wires are used, generating dumped
oscillations. Such oscillations and the associated overcurrent
and overvoltage levels reduce the LED life time and its efficiency
这种振荡和与之相关的过电流和过电压会降低发光二极管寿命及其效率。

[3]. To avoid or limit these effects the LED cannot be
driven by a mechanical relay but a smart driver is required to
control the slope of the LED current during transient, keeping it
为了避免或限制这些影响发光二极管不能由一个机械继电器控制但智能的驱动被要求需要在瞬态控制LED电流的斜率，以保持它在电线
的特征频率以下。

below the characteristic frequency of the wire. A compact and
efficient LED driver is needed, overcoming the above issues and
featuring a high flexibility to face different LED power levels,
一个紧凑和高效的LED驱动程序是必要的,是为了克服上述问题和具有高灵活性，去面对不同的发光二极管功率级别，连接拓扑和电线寄生。

connections topology, and wiring parasitics. Hereafter, Section
此后，在第二部分，分析了振荡和电磁干扰在放光二极管驱动中的影响。

II analyzes ringing and EMI problems in LED driving. Section
III presents the design of the new LED smart driver focusing on
第三部分介绍了一款新设计的智能发光二极管驱动的显著特征。

its distinguishing features. Section IV presents its experimental
第四部分介绍了发光二极管在不同功率等级下的实验特征，从几十毫瓦特
characterization with LEDs of different power levels, from tens
of milliwatts to several watts, used stand-alone, or connected in
到几瓦特在独立或几个连接下的状态。

strings. Temperature and voltage range operating conditions are
温度和电压等级的工作条件也被测量判断。

also measured. Conclusions are drawn in Section V.
第五部分将引出结论。

II. RINGING AND EMI PROBLEMS IN LED DRIVING
二.振荡和电磁干扰在发光二极管驱动中的影响
At state-of-the-art LED, driving is implemented using lowdrop
out linear regulators, which are limited to LEDs of few tens
of milliamperes, or more power-efficient switching solutions at
higher current levels
在最开始的LED,开车是使用低输出线性稳压器,仅限于几十毫安级的发光二极管,或更省电转换解决方案用在更高的电流水平。

[3]–[10]. However, a compact solution integrating
然而,一个紧凑的集成解决方案在一个单芯片数字ECU接口,
on a single chip a digital ECU interface, a low-power
configurable logic core, a power part able to work in linear mode
or switching one, as well as advanced techniques such as Soft
Start and Current Slope Control, has not been proposed yet in
一个低功耗可配置的逻辑核心,电源部分能够工作在线性模式或转换它,以及先进的技术,如软开始和电流升降调节，还没有在文献中被提出。

the literature. The main difficulties in the design of a universal
设计一个足够的灵活的发光二极管驱动应用在不同的接线配置
最大的难题是振荡和电磁干扰问题。

LED driver, flexible enough to be applied to different wiring
configurations, are the ringing and EMI issues. These problems
这些问题取决于环境因素和寄生组件，这些因素很难去假设和模仿。

depend on environmental and parasitic components that are difficult
to predict and simulate.While bulbs are easily modeled as
而电灯泡却很容易模仿因为它有线性的正温度系数并且寄生成分对它的影响比较小。

linear positive temperature coefficient (PTC) resistors, and are
less sensitive to parasitic components, a LED is a special diode
发光二极管是一种特殊的二极管，它满足肖克利指数电流-电压法。

and follows the Shockley exponential I–V law. A very small
fluctuation on the voltage across the LED can generate a very
一个很小的电压起伏通过发光二极管可能引起一个很大的电流变化
影响。

high variation on its current affecting, as proved in [3], both efficiency
经证明，效率和照明设备的寿命都将被影响。

and life time and creating lighting disturbs. This behavior
如果发光二极管没有恰当的被驱动的话这个行为会导致振荡和高强度的电流尖脉冲。

can generate ringing and high current spikes if the LED is not properly driven. By the same token, a bulb-designed driver, as
出于同样的原因，灯泡的驱动，正如10-12中说的，不能被直接用于驱动发光二极管。

shown in [10]–[12], cannot be directly used to drive efficiently
LEDs. This is particularly true when the LED and the driver are
这一点是完全正确的当发光二极管和驱动在汽车连接中被几米的电缆分割的时候。

separated by a few meter cables as in automotive connections.
In this case, the wiring parasitics can generate ringing and EMI.
出于这个原因，电线的寄生将引起振荡和电磁干扰。

A comparison based on experimental measurements, between
一个在二瓦特的灯泡和0.1瓦特的连着很短的线（大概10厘米长）发光二极管的比较实验中显示在图1和图2中。

a 2-W bul
b lamp and a 0.1-W LED turn-on transient with very
short wire (about 10 cm long) and with very long wire (about
3m long) is shown, respectively, in Figs. 1 and 2. A simple
relay is used as a switch to highlight the different behavior
一个简单的继电器被用来切换到这些负载不同的状态。

of those loads. Those pictures show the necessity of using a
这些图片展示了使用一个设计良好的LED驱动从而避免寄生电路的重要性。

well-designed driver for LEDs, to avoid unwanted effects due
to wiring parasitics. In fact, the behavior of the current in the
事实上，灯泡的电流状态不随着线的长度而变化。

[从图1a图2a可以看出]
bulb does not change significantly with the wire length [see
Figs. 1(a) and 2(a)] while the transient of the current in the
而发光二极管的瞬间电流缺有显著的差异。

[从图1b和2b可以看出] LED shows significant differences [see Figs. 1(b) and 2(b)]. To
overcome this issue we propose a compact solution, integrating
为了解决这个问题我们计划了一个简洁的方案：
in 0.35-μmHVCMOStechnology the digital circuitry for driver
interfacing/configuration and power devices up to 10W, with
采用高压CMOS技术数字电路的驱动程序，接口/配置和功率设备提高到10 瓦特
HV protection up to 55V. The LED driver can be interfaced to
同时高压保护提高到55伏特。

LED驱动可以被显示到数字电子控制单元，
digital ECU [13]–[15] and is able to cope with different wiring
从而它可以处理各种长度的电线配置和寄生电路。

configurations some meters long and their parasitics [2], and to
使其适应作为线性稳压器和开关的表现，取决于编程的精度。

adapt its behavior working as linear regulator or as a switching
one, depending on a programmable threshold.
III. FLEXIBLE LED DRIVER IC
三. 灵活的发光二极管驱动集成电路
With respect to the bulb lamp driver shown in [11], [12] the
关于指示灯驱动器了，智能LED驱动必须满足严酷的汽车环境约束。

smart LED driver needs to fulfill the same harsh automotive environment constraints, as well as more power demanding loads,
同时也要满足更多的功率负载需求用于串联和并联配置下的发光二极管。

as series and parallel configuration of LEDs. Low power LEDs,
like those employed in the car dashboard, absorbing 30–50mW,
像那些30-50毫瓦的用于汽车仪表盘的低功率发光二极管，包括那些排列在一起的总功率到10瓦特的发光二极管或灯泡，能被提议的设计驱动。

as well as arrays of power LEDs or lamps up to 10W, can be
driven properly by the proposed design.
图1.（a）灯泡（b）发光二极管在没有任何电流电压
控制的10厘米电缆下状态
图2 （a）灯泡（b）发光二极管在没有任何电流电压控制3厘米电缆下状态
图3. 方案一允许的负载配置,加强了布线寄生现象, 发光二极管,和串联的电池中的开关。

图4.LED驱动集成电路的体系结构和详细电路
The driving of LEDs has required the implementation of specific techniques to limit the undesired effects of wiring parasitics,
发光二极管的驱动要求实施特定的技术来限制布线寄生现象带来的不良影响。

such as ringing andconsequent overshoots and undershoots
如振荡和随之引起的超调量和脉冲信号。

.In Fig. 3, the scheme of the wiring parasitic and of a possible connection between
the driver and the load is shown: the output pin of the driver,
在图三中，该计划的布线寄生和可能的在驱动和负载的连接中显示:输出的驱动程序，其功能可以用一个简单的开关描述，是连接发光二极管，并且和汽车的
whose functionality can be represented by a simple switch to
the ground, is connected to a LED, in series with the car battery
and another switch, controlled by the user through a button or
电池和另外一个开关连接，而用户通过一个按钮或点火钥匙来控制它。

the ignition key. The basic scheme of the flexible LED driver
is shown in Fig. 4, together with circuit details of the operational
这个灵活的发光二极管驱动基本方案以及电路详细的步骤和跨导放大器块如图四所示。

transconductance amplifier (OTA) block: the architecture
这个设计基于一个
is based on a voltage regulation loop inserted inside a linear loop
providing the current control capability.
插入在一个线性循环的电压调节回路以提供当前的控制能力。

The voltage regulationloop forces the output on a reference voltage, Vref , when 电压调节回路控制输出的是参考电压当低压测主电源开关串联二极管以提供反极性的容量给装置，是开启了。

the low side main power switch (power MOS in Fig. 4), in series with
the Diode that provides reverse polarity capability to the device,
is turn ON. The LED driver has been integrated as hard macrocell
LED驱动程序已经被集成在一个复杂的大容量的电池汽车控制单元集成电路中
in a complex automotive control unit IC, implemented in
Austria micro systems (AMS) 0.35 μm CMOS technology. Fig 5
被用在AMS0.35UM的互补金属氧化物半导体技术中。

从图5中可以看出，
shows the layout and the photo of the whole control unit IC,
布局和图片的整个控制单元集成在电路中，使得发光二极管驱动电子电路增强。

highlighting the LED driver circuit, and particularly the power
MOS and its protection diode in Fig. 4, which occupy most of
the LED driver area.
特别的在图四中的MOS材料和二极管的保护，占绝了绝大部分的发光二极管驱动电路。

By regulating the output voltage on a reference level the state
of the load and of the power switch can be easily detected.
通过调节输出电压在一个参考电平状态的负载和电源开关可以很容易地被检测到。

When the LED is ON (user switch and power switch in Fig. 3
当发光二极管打开，（用开关或者图3的电源开关都可以使运转）both enabled), the regulation loop is activated and the output
调节回路是激活的，输出电压是控制为参考电压的。

Vo is forced on the reference voltage, Vref . If the user switch
同时强制发光二极管也关闭，如果关闭开关,因此发光二极管也关闭is OFF, and hence also the LED is OFF, the output pin of the
driver is pulled down even when the power switch is OFF, by
输出引线驱动被损坏甚至电源总开关也关掉，意味着编的程序没有应
变能力。

means of a programmable resistive path to ground. That path
is highly resistive to limit to very low value the current flowing
through the LED. Finally, if the user switch is ON but the
这条道路的高电阻是用来限制非常低的电流来通过发光二极管，如果用户开关打开但电源开关关闭，那么输出电压将强迫输出为电源的额定电压。

power switch is forced OFF, then the output Vo is pulled up to
the battery voltage, Vbatt , and the LED is OFF since no noticeable
发光二极管也将关闭直到没有明显的电流通过。

current is flowing. Summarizing, depending on the status
of the switch devices in Fig. 3, the output voltage Vo can be
pulled down to ground, or pulled up to Vbatt or forced to Vref .
根据不同开关设备的状态，如图3所示,输出电压可以接地,或者强迫为电源的额定电压。

A comparator can reveal the status of the driver and also potential
overvoltage conditions by comparing the output voltage
to proper thresholds. Similarly overcurrent and overtemperature
一个比较器可以显示驱的状态和通过比较输出电压合适的阈值看出潜在的过压条件。

phenomena can be detected by comparing the measured current
and temperature values (through an on-chip temperature sensor)
with proper thresholds. All reference and threshold levels are
同样的过电流和超温现象是可以探测到的测量的电流和温度的值(通过一个芯片上的温度传感器)和适当的阈值比较。

internally generated by a digital-programmable band-gap unit.
所有的引用和阈值水平是由内部产生的数字通过可编程的带隙装置。

The measurements shown in this letter are obtained with a Vref
这篇文章中的测量值是通过额定电压获得，1.2伏特。

of 1.2V. The detected driver and load status are used by the
internal logic as feedback signals to properly drive the power
MOS in Fig. 4, acting as linear regulator or ON–OFF switch,
检测到的驱动和负载状态使用内部逻辑作为反馈信号正确驱动动力在图四中的金属氧化物半导体,是作为线性调节器或开关
and implementing advanced Soft Start or Current Slope Control techniques.
和实施先进的软启动或电流升降控制技术
The working mode of the LED driver, as linear regulator or
ON–OFF switch, is determined by the user by proper configuring
the Current level Iref in Fig. 4. The MOSMA mirrors a small
工作模式的LED驱动,线性调节器或通断开关,是由用户通过适当的配置在图4按图四的电流是水平。

fraction of the power MOS output current and, through the HV
and Low-Voltage (LV) current mirrors in Fig. 4,
MOSMA反射小部分功率从MOS输出电流,如图四通过高压和低压(LV)电流反射镜镜，
compares it to the Iref current value (generated through on-chip band-gap circuit).
比较其当前值(通过芯片上的带隙电路生成Iref)。

The HV PMOS current mirror is connected to the output
voltage, which is up to 12V, while the LV PMOS current mirror
is connected to Vdd = 3.3V. The difference between Imir and
高压PMOS的电流反射连接到输出电压提高到12伏特,而低压PMOS电流反射连接到Vdd是3伏特。

Iref drives the gate of MOS MB : if Imir is lower than Iref , then
Imir和Iref之间的在MOS驱动上的区别是：如果Imir低于Irel，那么MB是关闭的
MB is OFF and the power MOS, driven by the OTA in Fig. 4,
并且MOS的能量是由如图四中的OTA驱动的，通过线性的电流调节器。

acts as a linear current regulator. Otherwise, MB is ON and the
反之，如果MB是打开的而电流环路控制开关关闭，那么MOS MB将会被
强制关闭。

current loop control switches to the OFF state the power MOS.
The MOS MB can be forced back in OFF state, and hence the
同时强制电源MOS起作用，如图四用来进行逻辑控制。

powerMOS reactived, by the control logic in Fig. 4. The control
logic determines the times Ton and Toff when MB is OFF (i.e.,
这个控制逻辑决定什么时候开什么时候关分别当MB关掉的时候（MOS 开着）
power MOS is ON) or MB is ON (i.e., power MOS is OFF), respectively.
或者MB开着（MOS关闭）
In this case, the driver is working in ON–OFF switch
因此，这个驱动工作在关或开的模式为了满足控制逻辑不停的变换开关。

mode with duty cycle and frequency depending on the Ton and
Toff times set by the control logic.
Summarizing, in linear regulator mode Iref is configured so
that the current loop control is activated only for output currents
of several amperes, much higher than the operating load currents
总结,在线性调节器模式Iref是如此配置的为了电流环路控制输出电流只有安培。

foreseen for this LED driver (see Section IV). In linear mode,
远高于操作负载电流的LED驱动程序(见第四部分)。

在线性莫模型中，Iref acts as a protection threshold: if Imir is over Iref then MB is
Iref担当着一个保护的临界值：当Imir超过了Iref，那么MB会打开，电源MOS会关闭。

switched ON and the power MOS is switched OFF.
In ON/OFF switching mode, Iref is configured at levels lower
在开/关模式下，Iref是按从低到高电流等级配置的。

than normal operating currents: the power MOS is no directly
driven by the OTA and the combined action of the current loop
control and of the control logic on the MOS MB determines the
Ton and Toff periods (and hence the switching duty cycle and
frequency) of the power MOS. To be noted that in switching
电源MOS没有直接被OTA和联合作用的电流环路控制。

同时控制逻辑在MOS MB上决定了开或者关的周期(因此切换工作周期和频率)。

mode Iref is not acting as the sole current limitation level; the
detection of overcurrent phenomena is carried out by the Over-
I and Over-V detect block in Fig. 4. The described approach
注意,在切换模式Iref不是作为唯一的电流限制水平;检测过流现象是被运用于过压过流检测块,如图4所示。

allows to implement two functions in the same LED driver IC at
minimal hardware overhead: linear regulator mode, useful for
所述方法可以实现两个功能相同的LED驱动集成电路在最小的硬件开销:线性稳压器，用于瞬间的变化和低电流低功率LED，当电源效率不是问题的时候。

fast transient and low-current/low-power LEDs, where power
efficiency is not an issue; switch driving mode, useful for higher
开关驱动方式，用于高电流和高功率LED，当电源效率是关键问题所以
current and higher power LEDs where the power efficiency is a
key issue and therefore a switching regulator has to be preferred
to a linear one.
线性的开关稳压器将被成为首选。

The driving of a LED calls also for specific strategies to
avoid the ringing phenomenon on the connecting wire with
the consequent current overshoot. The Soft Start and Current
发光二极管的驱动也要求具体策略在连接线上避免振荡现象与随之产生的电流超调。

Slope Control techniques, proposed by the authors in [12] for
bulb lamp driving (low-power dashboard indicator), have been
improved to maintain the same proper behavior also with arrays
of LEDs and high luminosity up to 10W. The design has taken
软启动和电流斜率控制技术,作者在[12]中提出的灯泡驱动(低功耗
仪表板指示器),被用来保持适当的状态，同时也排列二极管把光度提高到10瓦特。

into account the variability of parasitic capacitors and inductors,
设计已经考虑到可变性的寄生电容和电感,
as well as of the load and all process-voltage-temperature (PVT)
以及负载和所有过程电压温度(PVT)的部分。

corners. As shown in Fig. 6, by sweeping through different
如图六所示，通过不同的布线寄生现象和等效电阻
对不同负载配置的发光二极管，
values of the wiring parasitics and of the equivalent resistance
for different LED-based load configurations, the phase margin
电压调节回路的相位补角,如图4所示，在一个相关的方式下变化。

of the voltage regulation loop in Fig. 4 changes in a relevantway.
As a consequence, the susceptibility to instability of the overall
因此，
circuit varies, along with the entity of the ringing, as illustrated
不稳定的磁感系数的整体电路的变化,随着实体振荡，在图7中阐述的那样。

in Fig. 7. To deal with the wider range of possible values for the
load, compared to the previous bulb case study [12], the Current
处理各种复杂的负载的可能值,相比前一个灯泡案例研究[12], Slope Control, previously realized as a fixed technique, has
been tuned and made programmable through a digital interface.
当前电流控制,先前意识到作为一个完善的技术,已经被调整好并通过数字接口使其可编程。

The output current slope during the turn-on phase of the load
depends on how fast that power MOS is switched ON.
输出电流斜率在开机阶段的负载取决于MOS的开关开启的速度。

Sincethe power MOS in Fig. 4 is driven by the output of the OTA, by
因为操作系统的是由OTA的输出驱动的，如图4，
controlling its slew rate it is possible to control the load current
slope. The slew rate of the OTA can be controlled by tuning
the dimensions of the transistors that compose the OTA (fixed
mode implemented in [12]) or by regulating its bias current, Ibias
通过斜率。

转换速率可以控制通过调整控制它的转换速度,可以控制负载电流晶体管的尺寸组成OTA(固定模式实现在[12])或通过调节其偏置电流。

in Fig. 4, as done in this letter. Ibias is a configurable current
在图四，像这文章中说的，偏置电流是一个可配置的电流所产生的一个芯片上的带隙电路。

generated by an on-chip band-gap circuit. The programmability
of the Current Slope Control allows the employment of the smart
driver with different LEDs configuration, in order to keep down
the ringing.
这个可编程的电流升降控制允许使用的智能与不同的发光二极管驱动配置,为了降低偏振。

The supported switch driving mode is also useful to enable
the implementation of a Soft Start strategy against in-rush currents
that can cause overshoots and ringing phenomena. When
被支持的开关驱动方式也是用于启用实现软启动战略应对在高峰电流可引起超调量和偏振现象。

the output current lasts over a configurable current limit for
more than a configurable lapse of time, a Soft Start strategy is
当输出电流持续超过一个可配置一段时间的电流限制时,一个软启动策略将被采用，
adopted, switching the load by modulating the duty cycle and the
frequency (i.e., Ton and Toff ) parameters and hence controlling
the length of the turn-on phase.
开关负载的调制周期频率频率(即T开和T关)参数,从而控制开机阶段的相位。

As application example in Fig. 8, the time necessary to reach
the steady luminous state of a 10Wload can be greatly reduced
by modifying the duty cycle of the control signal (e.g., from
33% to 72% in the example of Fig. 8). Therefore, the Soft Start
作为应用在图8的例子,必要的时间到达稳定的发光状态10 w负载可以大大降低
通过修改工作周期的控制信号(如,从33%到72%的例子,图8)。

strategy is a particular way of using the current control loop in
Fig. 4 and the control logic acting on the MB and the power
MOS transistors not for power efficiency issues, but to face inrush
因此,软启动方式是一种特定的方式来使用该电流控制回路，在图4控制逻辑作用于MB金属氧化物半导体晶体管的能量不是功率效率问题，
currents during fast turn-on LED transients. The drawback
但需要面对快速瞬变电流刺激的涌入。

by pushing this strategy to optimize time performance is the
risk of a die-overheating by supplying the maximum current
for a long period. To this aim, Over-Temperature Protection,
using on-chip temperature sensor, is integrated into the driver to
缺点是按这个策略来优化时间性能的的风险通过会长时间提供模具过热的最大电流。

为达此目的,过热保护,使用芯片上的温度传感器。

prevent the device to be damaged, by turning to a standby mode
the entire driver until a sufficient cooling has occurred.
集成到驱动为了防止设备损坏,转向一种待机模式直到整个驱动都变得足够冷却。

Finally, the device presents a low power absorption, a feature
extremely important for a LED driver IC. As shown in Table I,
最后,该设备提供了一个低功率吸收的一个功能非常重要的LED驱动集成电路。

the power absorbed by the logic controlling the power switching
如同在一部分提到的那样，逻辑控制功率切换控制着功率吸收。

TABLE I
POWER PERFORMANCE OF THE PROPOSED SMART DRIVER
表格1
智能驱动的动力性能
TABLE II
WIRING PARASITIC ESTIMATION
表格2
寄生接线的估算
MOS is almost negligible during turn OFF and power down
phases, and it is very low even during the turn ON of the load,
with a maximum of 1.2mW while driving a 1A load.
MOS在关掉电源中断阶段是几乎可以忽略不,即使它是在打开的负载情况下也是非常低的，大概最大在1.2 微瓦当带一个负载的时候。

The main power switch MOS has been designed with a high
aspect ratio W/L to minimize its drain-to-source on resistance
and hence to minimize the power dissipation during the turn-on
主电源开关MOS已经被设计为一个高纵横比W / L来减少它的漏源极导通电阻从而来减少在开机阶段功耗。

phase. In experimental measures with 12 and 14V batteries,
Vref set to 1.2V, and 1A load, the power consumption is limited
to 1.2W over 12W and 14W, respectively (i.e., the measured
在实验时候用12和14 伏特的电池,Vref设置为1.2 伏特,一个1安培的负荷,功率消耗是限制分别在1.2瓦特到12瓦特和14瓦特。

（测量功率效率要达到91.4%以上）
power efficiency is up to 91.4%). The minimum Vref value
is roughly 0.7V, limited by the voltage drop on the diode in
最低Vref值大概是0.7伏特,二极管的电压降限制如图4所示。

Fig. 4. Hence, with 1-A load current the power consumption
of the driver would be roughly 0.7W and, considering a 12-V
battery system, this leads to a maximum power efficiency of
因此,如果负载电流的功率消耗的驱动都是大概在0.7瓦特,考虑一个
12伏特电池系统, 这令最大的功率效率为95%.
95%. The smart power IC in Fig. 4 can sustain voltage from
–15 to 55V and temperature from –40 to 150 ◦C. It has an area
在图四中的智能功率集成电路可以维持电压从-15伏特到55伏特，温度从-40摄氏度到摄氏度。

of 1.44mm2 , dominated by the power MOS and its protection
它的面积为1.44平方毫米,主要由功率MOS及其保护的二极管。

diode.Atradeoff was found between increased area of the power
MOS and reduction of its on-resistance and hence of the power
consumption.
关掉被发现增加了区域之间MOS以及减少电阻，因此增加了功率消耗。

IV. EXPERIMENTAL RESULTS
五.实验结果
The behavior of the proposed smart driver was evaluated
and experimental results are shown. Real automotive cables
对上述行为进行了评估,并提出了智能驱动实验结果显示。

were measured and then the extracted parasitic components, see
真实汽车电缆用于测量,然后提取寄生元件,从表格2可以看出，被用于以下测量值。

Table II, are used for the following measurements. According
to the scheme in Fig. 9, Fig. 10 compares the results achieved
with our driver without slope current control [see Fig. 10(a)]
根据在图9图10取得的结果进行比较发现我们的驱动没有电流升降控制。

and with slope current control enabled [see Fig. 10(b)] when the
load is the series of three 0.1WLEDs with only 50mA forward
和升降电流控制时使当负载是三个0.1瓦特led灯串联时只有50毫安
的正向偏压。

biased. In this case, without the current slope control, ringing
phenomena can occur. This can be avoided thanks to the slope
在这种情况下,没有电流升降控制、振荡现象会可以发生。