Maxim MAX16834大功率LED驱动方案(1)论文

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翻新时间：2013-12-18

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Maxim MAX16834大功率LED驱动方案(1)论文

Maxim 公司的MAX16834是集成了高边LED电流检测和PWM调光MOSFET驱动器的大功率LED驱动器。这种恒流模式高亮度LED（HBLED）驱动器适合于升压，升-降压，SEPIC和高边降压拓扑。

工作电压从.4.75V到28V，PWM调光/模拟调光比3000：1，可编程工作频率100kHz到1MHz，主要应用在单串LED LCD背光，汽车前后灯照明，投映RGB LED光源，环境照明和DC-DC升压/降压－升压转换器。本文介绍了MAX16834主要特性，方框图以及多种应用电路。

High-Power LED Driver with Integrated High-Side LED Current Sense and PWM Dimming MOSFET DriverThe MAX16834 is a current-mode high-brightness LED (HB LED) driver for boost, boost-buck, SEPIC, and highside buck topologies. In addition to driving an n-channEL power MOSFET switch controlled by the switching controller, it also drives an n-channel PWM dimming switch to achieve LED PWM dimming. The MAX16834 integrates all the building blocks necessary to implement a fixed-frequency HB LED driver with wide-range dimming control.The MAX16834 features constant-frequency peak current-mode control with programmable slope compensation to control the duty cycle of the PWM controller.A dimming driver designed to drive an external n-channel MOSFET in series with the LED string provides wide-range dimming control up to 20kHz. In addition to PWM dimming, the MAX16834 provides analog dimming using a DC input at REFI. The programmable switching frequency (100kHz to 1MHz) allows design optimization for efficiency and board space reduction.A single resistor from RT/SYNC to ground sets the switching frequency from 100kHz to 1MHz while an external clock signal at RT/SYNC disables the internal oscillator and allows the MAX16834 to synchronize to an external clock. The MAX16834’s integrated highside current-sense amplifier eliminates the need for a separate high-side LED current-sense amplifier in boost-buck applications.The MAX16834 operates over a wide supply range of 4.75V to 28V and includes a 3A sink/source gate driver for driving a power MOSFET in high-power LED driver applications. It can