austriamicrosystems AG is now ams AG The technical content of this austriamicrosystems datasheet is still valid. Contact information: Headquarters: ams AG Tobelbaderstrasse 30 8141 Unterpremstaetten, Austria Tel: +43 (0) 3136 500 0 e-Mail: ams sales ams.com Please visit our website at www.ams.com Dat a Sh eet AS1101, AS1102, AS1103, AS1104 Low-Dropout LED Drivers 1 General Description 2 Key Features LED Drivers for Parallel-Connected LEDs The AS1101/AS1102/AS1103/AS1104 are LED drivers designed to match current source bias for any color Ultra-Low Voltage Drop: Less Than 150mV (for Li- LED, including white and blue. The devices can drive up ion Battery Support) to 4 high-current LEDs, and the LED current is program- Analog and PWM Brightness Control mable using an external resistor (RSET). Up to 80mA per LED (AS1101) The AS1101 LED currents are 460 x ISET (per LED, typ) Up to 40mA per LED (AS1102, AS1103, AS1104) at an LED cathode voltage (VSAT) of 150mV and 650 x ISET (typ) at a VSAT of 1V, where ISET is the current No Electromagnetic Interference, No Switching- through RSET connected to pin CTRL. Noise The AS1102, AS1103, and AS1104 LED currents are Current-Matching Requires No External Compo- 230 x ISET (per LED, typ) at a VSAT of 150mV and 325 x nents ISET (typ) at a VSAT of 1V. Active-Low Shutdown Mode (AS1101, AS1102, The AS1101, AS1102, and AS1104 incorporate a chip- and AS1103) enable feature via pin ON. When the devices are dis- Low Shutdown-Current: Less Than 1A abled, the supply current drops to less than 1A. SC70-6 Package (AS1101, AS1102, and AS1103) The AS1101, AS1102, and AS1103 are available in a MSOP-8 Package (AS1104) 6-pin SC70 package the AS1104 is available in a 8-pin MSOP package. 3 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 Figure 1. Typical Application Diagrams DVD players, and consumer electronics. 2 Diode Control with Enable 3 Diode Control with Enable VIN VIN I1/I2 VSAT I3/I4 I1 VSAT I2 I3 ISET ISET VSET VSET (3V) (3V) RSET CTRL RSET CTRL AS1101 AS1102 ENABLE ENABLE ON ON GND GND 4 Diode Control 4 Diode Control with Enable VIN VIN I1 VSAT I2 I3 I4 I1 VSAT I2 I3 I4 ISET VSET ISET VSET (3V) CTRL RSET AS1103 AS1104 (3V) CTRL RSET ENABLE ON GND GND www.austriamicrosystems.com Revision 1.5 1 - 13 ams AG Technical content still valid