Date: 27/01/2010

High power WLED/RGB driver IC for medium LCD display backlighting

Allegro has introduced the A8501, a new high power WLED/RGB driver IC with output disconnect for backlighting medium LCD displays. The suggested applications for the A8501 driver IC are GPS navigation systems, automotive infotainment, back-up camera displays, cluster backlighting, portable DVD players, and industrial LCD displays.

The A8501 provides protection against output connector shorts through an integrated output disconnect switch. An optional external thermistor can be used to limit LED current based on panel temperature.

The key features of the A8501 LED driver IC are,

600 kHz to 2.2 MHz switching frequency ability to operate above the AM band
Internal bias supply for single-supply operation (VIN = 8 to 21 V)
Boost converter with integrated 40 V DMOS switch and OVP load-dump protection
3.5 µA of shutdown current limits battery drain
Active current sharing between LED strings for 0.8% current matching and 0.7% accuracy
Drive up to 9 series LEDs in 4 parallel strings, 36 LEDs maximum (Vf = 3.5 V, If = 100 mA)
LED sinks rated for 100 mA each (400 mA total)
PWM dimming with LED PWM duty cycle control
4000:1 dimming range
Output overvoltage protection (OVP): 19.5 V default can be adjusted as high as 38 V

Package: Surface mount, 28-pin TSSOP package (suffix LP)

For more details visit www.allegromicro.com