MAXIM 基于MAX16834实现112W高亮串型LED驱动方案
MAXIM公司的MAX16834是一款采用BOOST、BOOST-BUCK及高边BUCK拓扑结构的电流模式高亮LED驱动器。该芯片不但具有驱动一个功率N沟道MOSFET来驱动电源，而且还可以通过一个N沟道PWM开关实现LED的亮度调节。MAX16834集成了具有宽范围亮度调节所需要的恒频高亮度内嵌模块。该芯片具有外部使能引脚、内嵌振荡器、过温故障保护、开/短路保护及过压保护模块。本文通过介绍采用MAX16834的112W高亮LED参考设计，给出设计概述、电路设计板图、电路原理图、电子元器件列表、电路板各测试点波形图等，并给出设计中的设计注意要点，以便工程师快速实现设计。
This reference design uses the MAX16834 to create a high-powered LED driver for a very long string(s) of LEDs. The LED current is adjustable with a potentiometer, and can be set as high as 1.5A into as many as 20 LEDs (75V total). For long life, ceramic capacitors are used for both input and output decoupling.
This is a reference design for a 112.5W boost LED driver that uses the MAX16834 for long strings of LEDs. These long LED strings are commonly found in streetlights and parking garage lights.
Input voltage: 24VDC ±5% (at 1.49A)
VLED configuration: Two parallel strings. Each string consists of 19 WLEDs and a 5Ω resistor for current balancing. Current is 750mA per sting for a total of 1.5A into 75V.
Dimming: 50µs (min) on-pulse for up to a 200:1 dimming ratio with a 100Hz dimming frequency
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