安森美NCP5890背景光管理方案

安森美公司(On Semi)的NCP5890是用于LCD背景光和多个LED键盘背景光的照明管理集成电路,集成了三个独立的PWM用来控制LED,输入电压2.7到5.5V,输出电压可高达34V,并集成了环境光传感器,以调整光对比度,可用于手提设备的背景光和键盘照明以及照相手机的闪光灯.本文介绍了NCP5890的主要特性, 简化方框图, 基本架构图和多个白光LED应用电路图以及串联与并联扩展LED应用电路图.

NCP5890: Light Management IC (LMIC) for LCD Backlight and Multi-LED Keypad Backlight/ Fun lighting Applications
NCP5890主要特性:

34 V Output Voltage Capability
Include Three Independent PWM to Control LED Segments
2.7 to 5.5 V Input Voltage Range
90% Peak Efficiency with 4.7 _H / 150 m_ Inductor
Gradual Dimming Built−in
Integrated Ambient Light Sensing Adjusts Backlight Contrast
Built−in I2C Address Extension
Tight 1% I−LED Tolerance
True Cut Off Function Minimizes Load Leakage Current in Shutdown
Ultra Thin 0.5 mm QFN16 Package
This is a PB−Free Device

NCP5890典型应用:
Portable Back Light & Keyboard
Digital Cellular Phone Camera Photo Flash



图1.NCP5890简化方框图



图2.NCP5890基本架构图



图3.多个白光LED应用电路图



图4.串联PWM#1扩展LED应用电路图



图5.并联扩展LED应用电路图