AAT3112 Datasheet, PDF (12/16 Pages) Advanced Analogic Technologies – 500mA High Efficiency Charge Pump for White LED Flash Applications

Functional Block Diagram
AAT3112
500mA High Efficiency Charge Pump
for White LED Flash Applications
VIN
EN1
EN2
C2⁺
C2^-
Control
Circuit
Control
Circuit
S1
S2
S3
S4
S2
S1
S4
S3
C1 ⁺
C1 ^-
VOUT1
GND
VOUT2
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
C_IN, and one 10μF ceramic capacitor for C_OUT.
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.
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.
12
3112.2007.01.1.5