Allegromicro A8515高效白光LED驱动方案
Allegromicro公司的 A8515是宽输入电压范围高效多输出白光LED(WLED)驱动器,输入电压从5V到40V,最大LED电流120mA,LED电流精度0.5%,LED到LED电流匹配0.5%,集成了60V DMOS开关,可驱动多达12串LED灯(24个LED灯),开关频率高达2.25MHz,PWM调光,主要用在平板LCD屏以及平板视频显示屏.本文介绍了A8515主要特性和优势, 功能方框图以及多个典型应用电路.
Wide Input Voltage Range, High Efficiency Fault Tolerant LED Driver
The A8515 is a multi-output white LED (WLED) driver for LCD backlighting in consumer and industrial displays. It integrates a current-mode boost converter with an internal power DMOS switch and two current sinks. The boost converter can drive up to 24 LEDs: 12 LEDs per string at 120 mA. The LED sinks can be paralleled together to achieve higher LED currents, up to 240 mA. The A8515 can operate from a single power supply, from 5 to 40 V.
PWM dimming is implemented with an external PWM input signal. The PWM dimming pin is used to control the LED intensity by using pulse width modulation.
The low, 720 mV regulation voltage on the LED current sources reduces power loss and improves efficiency.
The A8515 is provided in a 16-pin TSSOP package (suffix LP) with an exposed thermal pad. It is lead (Pb) free, with 100% matte tin leadframe plating.
A8515主要特性和优势:
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