
Allegro MicroSystems
Description
The A8504 is a multi-output WLED driver for medium display backlighting. The A8504 integrates a boost converter and eight current-sinks to provide a WLED/RGB backlight driver. The boost converter can provide output voltage up to 47 V. The flexible channel selection control and high voltage capability allow a wide range of LED backlight applications.
▪ Thin notebook displays
▪LCD TV
▪RGB backlight
▪GPS systems
▪ Portable DVD players
FEATUREs and Benefits
▪ Active current sharing between 6 LED strings for ±1.3% typical current matching
▪ ±1.2% typical current accuracy
▪ Drive up to 11 series × 8 parallel = 88 LEDs (Vf = 3.5 V, If = 40 mA)
▪ External PWM control for LED dimming
▪ An external resistor for LED current setting
▪ Boost converter with integrated 50 V, 2 A DMOS
▪ LED sinks rated for 45 mA
▪ 200 kHz to 2 MHz switching frequency
▪ Open LED disconnect
▪ Boost current limit, thermal shutdown, and soft start
▪ No audible ceramic capacitor noise during PWM dimming
▪ Adjustable overvoltage protection (OVP)
▪ No pull-up resistors required for LED modules that use ESD capacitors