原标题：Maxim MAX16833高压高亮(HB) LED驱动方案

　　Maxim公司的MAX16833/B/C/D/G是峰值电流控制的LED驱动器,适用于升压,降压-升压,SEPIC,反激和高边降压拓扑.输入电压5V-65V,最大输出电压65V,集成了高边pMOS调光MOSFET驱动器和高边电流检测放大器,可编工作频率100kHz 到1MHz,具有短路,过压和热关断保护以及故障指示输出,工作温度-40°C到+125°C,主要用在汽车外部照明装置,商业,工业和建筑物照明.本文介绍了MAX16833优势和特性,功能框图,以及评估板MAX16833 EVK主要特性,电路图,材料清单和PCB设计图.

　　The MAX16833, MAX16833B, MAX16833C, MAX16833D, and MAX16833G are peak current-mode-controlled LED drivers for boost, buck-boost, SEPIC, flyback, and high-side buck topologies. A dimming driver designed to drive an external p-channel in series with the LED string provides wide-range dimming control. This feature provides extremely fast PWM current switching to the LEDs with no transient overvoltage or undervoltage conditions. In addition to PWM dimming, the ICs provide analog dimming using a DC input at ICTRL. The ICs sense the LED current at the high side of the LED string.

　　A single resistor from RT/SYNC to ground sets the switching frequency from 100kHz to 1MHz, while an external clock signal capacitively coupled to RT/SYNC allows the ICs to synchronize to an external clock. In the MAX16833/C/G, the switching frequency can be dithered for spread-spectrum applications. The MAX16833B/D instead provide a 1.64V reference voltage with a 2% tolerance.

　　The ICs operate over a wide 5V to 65V supply range and include a 3A sink/source gate driver for driving a power MOSFET in high-power LED driver applications. Additional features include a fault-indicator output (FLT) for short or overtemperature conditions and an overvoltage-protection sense input (OVP) for overvoltage protection. High-side current sensing combined with a p-channel dimming MOSFET allow the positive terminal of the LED string to be shorted to the positive input terminal or to the negative input terminal without any damage. This is a unique feature of the ICs.

　　MAX16833优势和特性:

　　Integration Minimizes BOM for High-Brightness LED Driver with a Wide Input Range Saving Space and Cost+5V to +65V Wide Input Voltage Range with a Maximum 65V Boost Output

　　Integrated High-Side pMOS Dimming MOSFET Driver (Allows Single-Wire Connection to LEDs)

　　ICTRL Pin for Analog Dimming

　　Integrated High-Side Current-Sense Amplifier

　　Full-Scale, High-Side, Current-Sense Voltage of200mV

　　Simple to Optimize for Efficiency, Board Space, and Input Operating RangeBoost, SEPIC, and Buck-Boost Single-Channel LED Drivers

　　2% Accurate 1.64V Reference (MAX16833B/D)

　　Programmable Operating Frequency (100kHz to1MHz) with Synchronization Capability

　　Frequency Dithering for Spread-Spectrum Applications (MAX16833/C/G)

　　Thermally Enhanced 5mm x 4.4mm, 16-PinTSSOP Package with Exposed Pad

　　Protection Features and Wide Temperature Range Increase System Reliability Short-Circuit, Overvoltage, and Thermal Protection

　　Fault-Indicator Output

　　-40°C to +125°C Operating Temperature Range

　　MAX16833应用:

　　Automotive Exterior Lighting: High-Beam/Low-Beam/Signal/Position Lights Daytime Running Lights (DRLs) Fog Light and Adaptive Front Light Assemblies

　　Commercial, Industrial, and Architectural Lighting

　　图1. MAX16833B/D功能框图

　　图2. MAX16833G功能框图

　　图3. MAX16833简化工作电路

　　图4. MAX16833/C应用电路图

　　图5. MAX16833G应用电路图

　　评估板MAX16833 EVK

　　The MAX16833 evaluation kit (EV kit) provides a proven design to evaluate the MAX16833 high-voltage HB LED driver with integrated high-side current sense. The EV kit is set up for boost and buck-boost configurations and operates from a 5V to 18V DC supply voltage. The EV kit is configured to deliver up to 1A to one string of LEDs. The total voltage of the string can vary from 3V to 36V. The anode of the LED string should be connected to the LED+ terminal. The cathode of the LED string can be connected either to the PGND (boost mode) or LED- (buck-boost mode) terminal. In the case of the boost mode, the input voltage should not exceed the LED string voltage.

　　The EV kit PCB comes with a MAX16833AUE+ installed, which is the frequency-dithering version. The EV kit also comes with the pin-compatible MAX16833BAUE+, which is the reference-voltage output version.

　　评估板MAX16833 EVK主要特性:

　　S Configured for Boost and Buck-Boost

　　S Analog Dimming Control

　　S Proven PCB Layout

　　S Fully Assembled and Tested

　　图6. 评估板MAX16833 EVK电路图

　　评估板MAX16833 EVK材料清单:

　　详情请见:

MAX16833-MAX16833G.pdf

MAX16833EVKIT.pdf