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