AAT3156

High Efficiency 1X/1.5X/2X Charge Pump for White LED Applications


Please note: this product is being discontinued and is not recommended for new designs.

The AAT3156 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 AAT3156 is capable of driving six-channel LEDs at 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 VIN and VOUT) make this part ideally suited for small battery-powered applications.

AnalogicTech's AS²Cwire™ (Advanced Simple Serial Control™) serial digital input is used to enable, disable, and set current for each LED with a 16-level logarithmic scale plus four low-current settings down to 50µA for optimized efficiency, with a low housekeeping current of only 50µA.

Each output of the AAT3156 is equipped with built-in protection for VOUT short circuit and auto disable for LED failure condition. Built-in soft-start circuitry prevents excessive inrush current during start-up. A low current shutdown feature disconnects the load from VIN and reduces quiescent current to less than 1µA.

The AAT3156 is available in a space-saving, thermally-enhanced 16-pin 4x4mm QFN package.

Note: Contact Sales for AAT3156 product availability.

Please note: AAT3156 is not recommended for new designs.

Specifications

Number of LEDs6
LED Channels6
LED(s) per/Ch1
Min. VIN (V)2.7
Max. VIN (V)5.5
InterfaceAS2Cwire™
Typ. IQ (μA)50
Peak Efficiency93%
Current Accuracy (%)±10%
Current Matching (%)±0.5%
Max. IOUT per/Ch (mA)30
PackageQFN, 16L
Package (mm)4 x 4 x 0.90
PackageQFN44-16

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 50µA
  • Low IQ (50µA) for Low Current Mode
  • Tri-Mode 1X, 1.5X, and 2X Charge Pump for Maximum Efficiency and VF Coverage
  • Drives Six Channels of LEDs
  • Individual Main/Sub-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 QFN44-16 Package

Product Documents