A S 11 0 1 , A S 11 0 2 , A S 11 0 3 , A S 11 0 4
Low-Dropout LED Drivers
D a ta S he e t
1 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 program-
mable using an external resistor (R
SET
).
The AS1101 LED currents are 460 x I
SET
(per LED, typ)
at an LED cathode voltage (V
SAT
) of 150mV and 650 x
I
SET
(typ) at a V
SAT
of 1V, where I
SET
is the current
through R
SET
connected to pin CTRL.
The AS1102, AS1103, and AS1104 LED currents are
230 x I
SET
(per LED, typ) at a V
SAT
of 150mV and 325 x
I
SET
(typ) at a V
SAT
of 1V.
The AS1101, AS1102, and AS1104 incorporate a chip-
enable feature via pin ON. When the devices are dis-
abled, the supply current drops to less than 1µA.
The AS1101, AS1102, and AS1103 are available in a
6-pin SC70 package; the AS1104 is available in a 8-pin
MSOP package.
2 Key Features
!
!
LED Drivers for Parallel-Connected LEDs
Ultra-Low Voltage Drop: Less Than 150mV (for Li-
ion 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 Compo-
nents
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)
!
!
!
!
!
!
!
!
!
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
DVD players, and consumer electronics.
3 Diode Control with Enable
V
IN
Figure 1. Typical Application Diagrams
2 Diode Control with Enable
V
IN
I1/I2 V
SAT
I
SET
V
SET
(3V)
R
SET
CTRL
ON
GND
I3/I4
I
SET
V
SET
(3V)
I1 V
SAT
I2
I3
AS1101
R
SET
CTRL
ON
AS1102
GND
ENABLE
ENABLE
4 Diode Control
V
IN
V
IN
4 Diode Control with Enable
I1 V
SAT
I2
I
SET
V
SET
(3V)
R
SET
CTRL
I3
I4
I
SET
V
SET
(3V)
I1 V
SAT
I2
I3
I4
AS1103
GND
R
SET
CTRL
ON
AS1104
GND
ENABLE
www.austriamicrosystems.com
Revision 1.5
1 - 13
AMSCO [ AUSTRIAMICROSYSTEMS AG ]
