AAT3167

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 AAT3167 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 AAT3167 is capable of driving five LEDs for a total of 135mA 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 115µA. For optimized efficiency, low-current mode settings require only 50µA of housekeeping current. Each output of the AAT3167 is equipped with built-in protection for VOUT short-circuit and auto-disable for load short-circuit conditions. 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 AAT3167 is available in a Pb-free, space-saving, thermally-enhanced, 16-pin, 3x4mm TDFN or 16-pin 4x4mm QFN package and is rated over the -40°C to +85°C temperature range.

Please note: AAT3167 is not recommended for new designs.

Specifications

Number of LEDs5
LED Channels5
LED(s) per/Ch1
Min. VIN (V)2.7
Max. VIN (V)5.5
InterfaceS2Cwire™
Typ. IQ (μA)50
Peak Efficiency94%
Current Accuracy (%)±10%
Current Matching (%)±0.5%
Max. IOUT per/Ch (mA)27
Package (mm)3 x 3, 4 x 4
PackageSTDFN33-14, QFN44-16

Features

  • VIN Range: 2.7V to 5.5V
  • Fully Programmable Current with Single Wire
  • 16-Step Logarithmic Scale
  • 14/18/27mA Max Current
  • Four Low Current Settings Down to 115µA
  • Low IQ (50µA) for Single-Channel, Low-Current Mode
  • Tri-Mode 1X, 1.5X, and 2X Charge Pump for Maximum Efficiency and VF Coverage
  • Drives up to Five LEDs
  • Individual Main-Sub (4-1) 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
  • TDFN34-16 or QFN44-16 Package

Product Documents