Supertex HV9986三路开关模式LED驱动方案
Supertex 公司的HV9986是外部重置的三路闭环开关模式LED驱动器,输入电压10V-40V,恒定频率1MHz,串-串电流精度为±2%,源电流0.25A,沉电流0.5A,采用线性和PWM调光,主要用在RGB背光,多串白光LED驱动器.本文介绍了HV9986主要特性,方框图和典型应用电路图.
Three-Channel, Closed-Loop, Switch Mode LED Driver IC with External Reset
The HV9986 is a three-channel peak current mode PWM controller for driving single switch converters in a constant output current mode. It can be used for driving either RGB LEDs or multiple channels of white LEDs.
The HV9986 features a 40V linear regulator, which provides a 5V supply to power the IC. The switching frequencies of the three converters in the IC are controlled either with an external clock signal (the channels operate at a switching frequency of 1/12th of the external clock frequency) or using the internal oscillator. The three channels are positioned 120° out-of-phase to reduce the input current ripple. Each converter is driven by a peak current mode controller with output current feedback.
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