HV9963設計的高壓LED驅動方案

本文介紹HV9963主要特性，功能方框圖和典型應用電路。
Supertex公司的HV9963是電流模式控制的LED驅動器，能用來控制PWM轉換器（降壓，升壓，升-降壓或SEPIC），PWM調(diào)光比大于5000：1，內(nèi)部有40V線性穩(wěn)壓器，±2%電壓基準，可編程軟起動和10V GATE驅動器，主要用在RGB或白光LED背光，電池能源LED燈，其它DC/DC LED驅動器。
The HV9963 is a current mode control LED driver IC designed to control single switch PWM converters (buck, boost, buck-boost or SEPIC) in a constant frequency mode. The controller uses a peak current-mode control scheme (with programmable slope compensation) and includes an internal transconductance amplifier to accurately control the output current over all line and load conditions. Multiple HV9963s can be synchronized to each other or to an external clock using the SYNC pin. The IC also provides a disconnect switch gate drive output, which can be used to disconnect the LEDs in case of a fault condition using an external disconnect FET. The 10V external FET drivers allow the use of standard level FETs. The low voltage 5.0V AVDD is used to power the internal logic and also acts as a reference voltage to set the current level.

The HV9963 includes an enhanced PWM dimming logic (patent pending) that enables very high PWM dimming ratios. HV9963 also provides a TTL compatible, low-frequency PWM dimming input that can accept an external control signal with a duty ratio of 0-100% and a frequency of up to a few tens of kilohertz.

HV9963主要特性：

? Switch mode controller for single switch converters

● Buck

● Boost

● Buck-boost and SEPIC

? High output current accuracy

? High PWM dimming ratio (>5000:1)

? Internal 40V linear regulator

? Internal ±2% voltage reference

? Constant frequency operation with sync capability

? Programmable soft start

? 10V GATE drivers

? Hiccup mode protection for both short circuit and open circuit conditions

HV9963應用：

? RGB or white LED backlighting

? Battery powered LED lamps

? Other DC/DC LED drivers

圖1。HV9963功能方框圖

圖2。HV9963典型應用電路圖