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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
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