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) conversion to increase efficiency in white LED applications. With input voltages ranging from 2.7V to 5.5V, 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.

FEATUREs
• 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 Four 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°C to +85°C Temperature Range

APPLICATIONs
• Programmable Current Source
• White LED Backlighting