Supertex HV9961平均电流模式LED驱动方案

Supertex 公司的HV9961是平均电流模式控制LED驱动器,工作电压从8.0V到450V,输出LED电流精度为±3%,具有线性和PWM调光输入,工作温度从-40度到125度C,主要用在DC/DC或AC/DC KED驱动,LCD显示器的LED背光驱动,通用的恒流源,建筑物和装饰LED照明和LED街灯照明.本文介绍了HV9961主要特性,方框图以及典型应用电路.

The HV9961 is an average current mode control LED driver IC operating in a constant off-time mode. Unlike HV9910B, this control IC does not produce a peak-to-average error, and therefore greatly improves accuracy, line and load regulation of the LED current without any need for loop compensation or high-side current sensing. The output LED current accuracy is ±3%. The IC is equipped with a current limit comparator for hiccupmode output short circuit protection. The HV9961 can be powered from an 8.0 - 450V supply.

A PWM dimming input is provided that accepts an external control TTL compatible signal. The output current can be programmed by an internal 272mV reference, or controlled externally through a 0 - 1.5V dimming input.

HV9961 is pin-to-pin compatible with HV9910B and it can be used as a drop-in replacement for many applications to improve the LED current accuracy and regulation.

HV9961主要特性:

• Fast average current control
• Programmable constant off-time switching
• Linear dimming input
• PWM dimming input
• Output short circuit protection with skip mode
• Ambient operating temperature -40OC to +125OC
• Pin-compatible with the HV9910B

HV9961应用:

• DC/DC or AC/DC LED driver applications
• LED backlight driver for LCD displays
• General purpose constant current source
• LED signage and displays
• Architectural and decorative LED lighting
• LED street lighting

图1.HV9961功能方框图

图2.HV9961典型应用电路