原标题：Infineon TLD5542－1同步MOSFET H桥DC－DC控制器解决方案

　　摘要: infineon公司的TLD5542-1是内置了保护特性和SPI接口的同步MOSFET H桥DC-DC控制器,特别适合于驱动具有最大系统效率和最少外接元件的大功率LED. TLD5542-1是单电感大功率降压-升压控制器,提供模拟和数字(PWM)调光,开关频率在200 kHz 到700 kHz间可调.LED正向电压在2V-55V),VIN电压范围宽(IC 4.5V-40V,电源4.5V-55V),每种条件下的效率高达96%. TLD5542-1具有恒流(LED)和恒压稳压器.由于快速输出放电操作,单个IC可驱动多个负载.LED和输入电流检测有专用的监测器输出,用于器件和负载的先进的保护特性. LED电流精度在+/- 3%.主要用在驱动多个大功率LED功能的特别设计,汽车外部照明,通用DC/DC电压稳压器.本文介绍了TLD5542-1主要特性,保护功能和诊断功能以及跛行模式功能,框图和稳压器框图,应用框图,以及TLD5542-1多路评估板V4.4主要电特性,电路图和PCB设计图.

　　The TLD5542-1 is a synchronous MOSFET H-Bridge DC/DC controller with built in protection features and SPI interface. This concept is beneficial for driving high power LEDs with maximum system efficiency and minimum number of external components. The TLD5542-1 offers both analog and digital (PWM) dimming. The switching frequency is adjustable in the range of 200 kHz to 700 kHz. It can be synchronized to an external

　　clock source. A built in programable Spread Spectrum switching frequency modulation and the forced continuous current regulation mode improve the overall EMC behavior. Furthermore the current mode regulation scheme provides a stable regulation loop maintained by small external compensation components. The adjustable soft start feature limits the current peak as well as voltage overshoot at start-up.

　　The TLD5542-1 is suitable for use in the harsh automotive environment.

　　TLD5542-1主要特性:

　　• Single inductor high power Buck-Boost controller

　　• Wide LED forward voltage range (2 V up to 55 V)

　　• Wide VIN range (IC 4.5 V to 40 V, power 4.5 V to 55 V)

　　• Switching frequency range from 200 kHz to 700 kHz

　　• SPI for diagnostics and control

　　• Maximum efficiency in every condition (up to 96%)

　　• Constant current (LED) and constant voltage regulation

　　• Drives multiple loads with a single IC thanks to the Fast Output Discharge operation

　　• Limp Home function (fail safe mode)

　　• EMC optimized device: features an Auto Spread Spectrum

　　• LED and input current sense with dedicated monitor outputs

　　• Advanced protection features for device and load

　　• Enhanced dimming features: Analog and PWM dimming

　　• LED current accuracy +/- 3%

　　• Available in a small thermally enhanced PG-VQFN-48 or PG-TQFP-48 package

　　• Automotive AEC Qualified

　　TLD5542-1保护功能:

　　• Over load protection of external MOSFETs

　　• Shorted load, output overvoltage protection

　　• Input undervoltage protection

　　• Thermal shutdown of device with autorestart behavior

　　• Electrostatic discharge protection (ESD)

　　TLD5542-1诊断功能:

　　• Latched diagnostic information via SPI

　　• Device Overtemperature shutdown and Temperature Prewarning

　　• Smart monitoring and advanced functions provide ILED and IIN information

　　跛行模式功能:

　　• Limp Home activation via LHI pin

　　TLD5542-1应用:

　　• Especially designed for driving multiple high power LED functions (I.E. Low Beam, High Beam, DRL)

　　• Automotive Exterior Lighting: full LED headlamp assemblies

　　• General purpose DC/DC voltage regulator

　　图1. TLD5542-1框图

　　图2. TLD5542-1稳压器框图

　　图3. TLD5542-1应用框图:电流稳流器

　　图4. TLD5542-1应用框图:改善EMC性能的附加元件

　　图5. TLD5542-1应用框图:三功能LED驱动器模块

　　图6. TLD5542-1应用框图:可调电压稳压器

　　TLD5542-1多路评估板V4.4

　　The TLD5542-1 Multichannel evalboard V4.4 it is an evaluation platform for the TLD5542-1, which can drive 3 LED functions (HB, LB, DRL), with a single efficient DC/DC converter. The board shows good EMC performance, EMC report available for download on the evaluation board webpage.

　　The TLD5542-1 multichannel evalboard V4.4 it is an evaluation platform for the TLD5542-1, which can drive 3 LED functions (HB, LB, DRL), with a single efficient DC/DC converter.

　　In the single DC/DC multichannel system night-time functions (e.g. HB and LB) are connected in series and the complementary daytime (DRL) function in parallel by mean of switches (Figure 2). The switches properly distribute the DC/DC converter output current in order to obtain the requested LED currents. This approach is called multi floating switch (MFS) architecture.

　　图7.LED驱动器三功能MFS架构图

　　The TLD5542-1 Multichannel evalboard V4.4 has an ePower microcontroller TLE9842-2 pre-programmed with the application software V4.0 or higher. A PC GUI can configure load currents and duty cycles via USB (UART over LIN).

　　图8. TLD5542-1多路评估板V4.4外形图