General Description

The AAT3169 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 AAT3169 is capable of driving six LEDs for a total of 180mA 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 IN and OUTCP) make this part ideally suited for small, batterypowered applications.

Features

• VIN Range: 2.7V to 5.5V

• Fully Programmable Current with Single Wire

▪ 16-Step Logarithmic Scale

▪ 15/20/30mA Max Current

▪ Four Low-Current Settings Down to 115µA

▪ Low IQ (65µA) for Single-Channel, Low-Current Mode

• Tri-Mode 1X, 1.5X, and 2X Charge Pump for Maximum Efficiency and VF Coverage

• Drives Up to Six LEDs

• Individual Main-Sub (5-1) Group Control

• No Inductors, Low Noise Operation

• 1MHz Constant Switching Frequency

• Small Application Circuit

• Built-In Thermal Protection

• Built-In Auto-Disable for Open Circuit

• Automatic Soft Start

• IQ <1µA in Shutdown

• Thermally-Enhanced STDFN33-14 or QFN44-16 Package

Applications

• Color (RGB) Lighting

• Programmable Current Sink

• Transmissive Displays

• White LED Backlighting

• White Photo Flash for Digital Still Cameras