Data Sheet
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
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 (RSET).
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Ultra-Low Voltage Drop: Less Than 150mV (for Li-
ion Battery Support)
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Analog and PWM Brightness Control
Up to 80mA per LED (AS1101)
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.
Up to 40mA per LED (AS1102, AS1103, AS1104)
No Electromagnetic Interference, No Switching-
Noise
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.
ꢀ
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Current-Matching Requires No External Compo-
nents
Active-Low Shutdown Mode (AS1101, AS1102,
and AS1103)
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.
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Low Shutdown-Current: Less Than 1µA
SC70-6 Package (AS1101, AS1102, and AS1103)
MSOP-8 Package (AS1104)
The AS1101, AS1102, and AS1103 are available in a
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
DVD players, and consumer electronics.
Figure 1. Typical Application Diagrams
2 Diode Control with Enable
3 Diode Control with Enable
VIN
VIN
I1/I2 VSAT
I3/I4
I1 VSAT
I2
I3
ISET
ISET
VSET
(3V)
VSET
(3V)
CTRL
CTRL
ON
RSET
RSET
AS1101
AS1102
ENABLE
ENABLE
ON
GND
GND
4 Diode Control
4 Diode Control with Enable
VIN
VIN
I1 VSAT I2
I3
AS1103
GND
I4
I1 VSAT I2
I3
I4
ISET
VSET
(3V)
ISET
VSET
(3V)
CTRL
ON
RSET
AS1104
CTRL
RSET
ENABLE
GND
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