General Description

The AS1101/AS1102/AS1103/AS1104 are LED drivers designed to match current source bias for any color LED, including white and blue. The devices can drive up to 4 high-current LEDs, and the LED current is programmable using an external resistor (RSET). The AS1101 LED currents are 460 x ISET (per LED, typ) at an LED cathode voltage (VSAT) of 150mV and 650 x ISET (typ) at a VSAT of 1V, where ISET is the current through RSET connected to pin CTRL. The AS1102, AS1103, and AS1104 LED currents are 230 x ISET (per LED, typ) at a VSAT of 150mV and 325 x ISET (typ) at a VSAT of 1V.

Key Features

LED Drivers for Parallel-Connected LEDs

Ultra-Low Voltage Drop: Less Than 150mV (for Liion Battery Support)

Analog and PWM Brightness Control

Up to 80mA per LED (AS1101)

Up to 40mA per LED (AS1102, AS1103, AS1104)

No Electromagnetic Interference, No Switching Noise

Current-Matching Requires No External Components

Active-Low Shutdown Mode (AS1101, AS1102,and AS1103)

Low Shutdown-Current: Less Than 1µA

SC70-6 Package (AS1101, AS1102, and AS1103)

MSOP-8 Package (AS1104)

Applications

The AS110x devices are ideal for LED displays and key board backlights, as well as lighting management units for battery powered audio devices such as MP3 and CD players, mobile and cordless phones, PDAs, portable DVD players, and consumer electronics.