ADI AD5203 8串WLED驱动方案
ADI 公司的AD5203是集成了SMBus 和PWM输入的8串白光LED(WLED)驱动器,采用电流模式和升压转换器技术,具有高效率.AD5203集成了0.15 Ω, 2.9 A的开关,工作频率在350kHz和1MHz间选择.输入电压从6V到21V,最大输出电压可调至45V,调光频率在200Hz到10kHz间可调,具有LED开路和短路故障保护.主要用在笔记本电脑,UMPC和监视显示器.本文介绍了AD5203主要特性,方框图以及采用无延迟调光模式的SMBus接口, DPWM调光模式的PWM接口和DC电流调光模式的PWM接口的典型应用电路.
8-String, White LED Driver with SMBus and PWM Input for LCD Backlight Applications
The ADD5203 is a white LED driver for backlight applications based on high efficiency, current-mode, step-up converter technology. It is designed with a 0.15 Ω, 2.9 A internal switch and a pin-adjustable operating frequency between 350 kHz and 1 MHz.
The ADD5203 contains eight regulated current sources for uniform brightness intensity. Each current source can be driven up to 30 mA, and the LED driving current is pin adjustable by an external resistor. The ADD5203 drives up to eight parallel strings of multiple series connected LEDs with a ±1.5% current matching between strings.
The ADD5203 provides various dimming modes. Each dimming mode is selectable with an external dimming mode selection pin. The LED dimming control interface can be achieved through PWM input and/or SMBus.
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