General Description

The AAT3194 is a low noise, constant frequency charge pump DC/DC converters that use fractional (1.5X) conversion to increase efficiency in white LED applications. The devices can be used to produce current levels up to 20mA for each output from a 2.7V to 5.5V input. A low external parts count (two 1µF flying capacitors and two small bypass capacitors at IN and OUT) makes these devices ideally suited for small, battery-powered applications.

Features

• VIN Range: 2.7V to 5.5V

• 20mA Full-Scale Current

• Simple Serial Control (S2Cwire) Interface

▪ 32-Position Logarithmic Scale with Digital Control

• Low Noise Constant Frequency Operation

• 33 Less Input Current Than Doubler Charge Pump

• High Accuracy Brightness Matching

• Small Application Circuit

• Regulated Output Current

• Automatic Soft Start

• No Inductors

• 600kHz Switching Frequency

• IQ <1µA in Shutdown

• Temperature Range: -40°C to 85°C

• 12-Pin TSOPJW Package

Applications

• Programmable Current Source

• White LED Backlighting