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 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.
The AS1101, AS1102, and AS1104 incorporate a chipenable
feature via pin ON. When the devices are disabled,
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 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)
3 Applications
The AS110x devices are ideal for LED displays and keyboard
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.