ST公司的LED7706 是LCD屏背景光LED驱动器，包括一个高效率的升压转换器和六个可控电流发生器。LED7706是6列30mA LED驱动器。输入电压4.5V到36V，输入电压4.5V到36V，输出电压高达36V（每列可驱动10个白光LED），广泛应用在LCD监视器和TV屏，PDA屏背景光和GPS屏背景光。本文介绍了LED7706的主要性能特性，方框图以及典型应用电路。

6-rows 30 mA LEDs driver with boost regulator for LCD panels backlight

The LED7706 consists of a high efficiency monolithic boost converter and six controlled
current generators (rows) specifically designed to supply LED arrays used in the backlighting of LCD panels. The device can manage an output voltage up to 36 V (i.e. 10 white LEDs per row).
The generators can be externally programmed to sink up to 30mA and can be dimmed via a PWM signal (1 % dimming duty-cycle at 20 kHz can be managed). The device allows to detect and manage the open and shorted LED faults and to let unused rows floating. Basic protections (Output Over-Voltage, internal MOSFET Over-Current and Thermal Shutdown) are provided.

主要特性：
Boost section
4.5 V to 36 V input voltage range
Internal power MOSFET
Internal +5 V LDO for device supply
Up to 36 V output voltage
Constant frequency peak current-mode control
250 kHz to 1 MHz adjustable switching frequency
External synchronization for multi-device application
Pulse-skip power saving mode at light load
Programmable soft-start
Programmable OVP protection
Stable with ceramic output capacitors
Thermal shutdown
Backlight driver section
Six rows with 30 mA maximum current capability (adjustable)
Parallelable rows for higher current
Rows disable option
Less than 500 ns minimum dimming time (1 % minimum dimming duty-cycle at 20
kHz)
±2 % current matching between rows
LED failure (open and short-circuit) detection

应用：
LCD monitors and TV panels
PDA panel backlight
GPS panel backlight



图1. LED7706方框图



图2. LED7706应用电路

来源：ST