AAT3112
500mA High Efficiency Charge Pump
for White LED Flash Applications
Functional Block Diagram
VIN
S2
S4
S1
S3
C1+
C1-
Control
Circuit
EN1
VOUT1
Control
Circuit
EN2
GND
S1
S3
S2
C2+
C2-
S4
VOUT2
The AAT3112 is designed to deliver 200mA of con-
tinuous current and up to 500mA of pulsed current.
Each charge pump engine has an independent
enable pin to extend battery life. The charge pump
switching frequency is approximately 750kHz,
enabling the use of small external flying capacitors.
Functional Description
The AAT3112 is a dual charge pump intended for
high-current applications. This device boosts an
input voltage to a regulated output voltage.
Regulation is achieved by sensing the output volt-
age through an internal resistor divider network.
The AAT3112 requires only four external compo-
nents: two 1.0μF ceramic capacitors for the charge
pump (C1 and C2), one 10μF ceramic capacitor for
The AAT3112 has complete output short-circuit and
thermal protection to safeguard the device under
extreme operating conditions. An internal thermal
protection circuit senses die temperature and will
shut down the device if the internal junction tem-
perature exceeds approximately 145°C.
CIN, and one 10μF ceramic capacitor for COUT
.
12
3112.2007.01.1.5
ANALOGICTECH [ ADVANCED ANALOGIC TECHNOLOGIES ]
