General Description
The AAT3153 is a low noise, constant frequency charge pump DC/DC converter that uses a tri-mode load switch (1X), fractional (1.5X), and doubling (2X) conversion to maximize efficiency for white LED applications. The AAT3153 is capable of driving six LED channels from a 2.7V to 5.5V input. The current sinks may be operated individually or in parallel for driving higher current LEDs. A low external parts count (two 1µF flying capacitors and two small 1µF capacitors at VIN and VOUT) makes this part ideally suited for small, battery-powered applications.

Features
• VIN Range: 2.7V to 5.5V
• Fully Programmable Current with Single Wire
    — Eight-Step Current: 20mA to 50µA
    — Individual Main-Sub Group Control
    — Low IQ (50µA) at Light Load
• Tri-Mode 1X, 1.5X, and 2X Charge Pump for Maximum Efficiency and VF Coverage
• Drives Up to Six LED Channels
• No Inductors, Low Noise Operation
• 1MHz Constant Switching Frequency
• Small Application Circuit
• Built-In Thermal Protection
• Built-In Auto-Disable for Short-Circuit
• Automatic Soft Start
• IQ <1µA in Shutdown
• Thermally-Enhanced 4x4mm 16-Pin QFN Package

Applications
• Color (RGB) Lighting
• Programmable Current Sinks
• White LED Backlighting
• White Photo Flash for Digital Still Cameras