May 2009

Doc ID 14893 Rev 1

1/17

AN2810

Application note

6-row 85 mA LED driver with boost

converter for LCD panel backlighting

Introduction

The LED7707 LED driver from STMicroelectronics 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. ten white-LEDs per row). The generators can be externally

programmed to sink up to 85 mA and can be dimmed via a PWM signal (1% of minimum

dimming duty-cycle at 1 kHz can be managed). The device allows detection and

management of open and shorted LED faults, and permits unused rows to be left floating.

Basic protections (output overvoltage, internal MOSFET overcurrent and thermal shutdown)

are provided.

Figure 1.

LED7707 demonstration board

www.st.com