PRODUCT DATASHEET
AAT3103
ChargePump
TM
Pin Descriptions
Pin #
1
2
3
4
5
3-Channel Charge-Pump LED Driver
Symbol
D1
OUT
C-
C+
IN
EN/SET
(AAT3103-1/-2)
Description
LED1 Current Source Output. Connect LED1’s anode to D1 and its cathode to AGND.
Charge Pump Output. Bypass OUT to AGND with a 1μF or larger ceramic capacitor.
Charge Pump Capacitor Negative Node.
Charge Pump Capacitor Positive Node. Connect a 1μF ceramic capacitor between C+ and C-.
Power source input. Connect IN to the power source, typically the battery. Bypass IN to AGND with a
1μF or larger ceramic capacitor.
LED Enable and serial control input. EN/SET is the ON/OFF control for the LED and the S
2
Cwire digital
input for the AAT3103-1/-2 to control the LED brightness up to the maximum current set by R
SET
.
LED ON/OFF and PWM (Pulse Width Modulation) control input. This logic input controls the LED
outputs for the AAT3103-4. A PWM signal, ranging from 10% to 100% duty cycle, controls the LED
current linearly between minimum and the full-scale output set by R
SET
.
A 1% tolerance resistor from this pin to AGND sets the maximum LED current value. For optimal LED
output current accuracy and matching in the AAT3103-1/-2/-4, a 14.3kΩ resistor sets each full-scale
output current to 20mA.
Analog Ground. Connect this pin to the system’s analog ground plane.
LED3 Current Source Output. Connect LED3’s anode to D3 and its cathode to AGND.
LED2 Current Source Output. Connect LED2’s anode to D2 and its cathode to AGND.
6
EN/PWM
(AAT3103-4)
RSET
AGND
D3
D2
7
8
9
10
Pin Configuration
SC70JW-10
(Top View)
D1
OUT
C-
C+
IN
1
10
D2
D3
AGND
RSET
EN/SET (EN/PWM)
2
3
4
5
9
8
7
6
2
www.analogictech.com
3103.2008.03.1.0
AAT [ ADVANCED ANALOG TECHNOLOGY, INC. ]
