AAT3122 View Datasheet(PDF) - Advanced Analogic Technologies
Part Name
Description
MFG CO.
AAT3122
Advanced Analogic Technologies
'AAT3122' PDF : 12 Pages View PDF
AAT3122
High Efficiency 1X/1.5X Fractional Charge
Pump for White LED Applications
General Description
The AAT3122 is a low noise, constant frequency
charge pump DC/DC converter that uses a dual
mode Load Switch (1X) and fractional (1.5X) con-
version to increase efficiency in White LED appli-
cations. With input voltages ranging from 2.7-5.5
Volts, the device can produce an output current of
up to 120mA. A low external parts count (two 1µF
flying capacitors and two small bypass capacitors
at VIN and OUT) makes the AAT3122 ideally suited
for small battery-powered applications.
AnalogicTech™'s Simple Serial Control™
(S2Cwire™) interface is used to enable, disable
and set the LED drive current with a 32 level loga-
rithmic scale LED brightness control. The AAT3122
has a thermal management system to protect the
device in the event of a short circuit condition on
any of the output pins. Built-in soft-start circuitry
prevents excessive inrush current during start-up.
High switching frequency enables the use of small
external capacitors. A low shutdown current feature
disconnects the load from VIN and reduces quies-
cent current to less than 1µA. The AAT3122 pro-
vides a single current source output that can be
used to drive up to 6 LEDs at 20mA each. The
AAT3122 is available in a TSOPJW-12 package.
Features
ChargePump™
• VIN Range: 2.7V to 5.5V
• <1µA of Shutdown Current
• 1 MHz Switching Frequency
• Dual Mode 1x and 1.5x Charge Pump for
Maximum Efficiency
• Only 4 External components
• Simple Serial Control™ (S2Cwire) Interface
• Low Noise Constant Frequency Operation
• 33% Less Input Current Than Doubler Charge
Pumps
• Small Application Circuit
• Regulated Output Current
• Automatic Soft-Start
• No Inductors
• TSOPJW-12 Package
• -40 to +85C° Temperature Range
Applications
• White LED Backlighting
• Programmable Current Source
Typical Application
VBATTERY
CIN
COUT
1µF
1µF
EN/SET
VIN
C1+
AAT3122
VOUT
C1-
C2+
C2-
EN/SET
D
GND
C1
1µF
C2
1µF
D1
D2
D3
D4
D5
D6
3122.2004.08.1.2
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