AAT3143

High Efficiency 1x/1.5x/2x Mode Charge Pump with PWM Control for White LED Applications


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

The AAT3143 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 AAT3143 can deliver current levels up to 80mA to connect white LEDs connected to the four current source outputs from a 2.7V to 5.5V input. The current source outputs may source up to 20mA each and may be operated individually or in parallel for driving higher-current LEDs. A low external parts count (two 1F flying capacitors and two small 1F capacitors at VIN and VOUT) makes the AAT3143 ideally suited for small battery-powered applications.

Output current, and therefore brightness, is controlled via externally applied Pulse Width Modulation (PWM) control. Typically, PWM frequencies of up to 50kHz can be applied.

The AAT3143 has a thermal management system to protect the device in the event of a short-circuit condition at the voltage output pin. Built-in soft-start circuitry prevents excessive inrush current during start-up. A high charge pump switching frequency allows the use of very small external capacitors. A low current shutdown feature disconnects the load from VIN and reduces quiescent current to less than 1µA.

The AAT3143 is available in a Pb-free, space-saving, 2.85x3.0mm 12-pin TSOPJW package.

Please note: AAT3143 is not recommended for new designs.

Specifications

Number of LEDs4
LED Channels4
LED(s) per/Ch1
Min. VIN (V)2.7
Max. VIN (V)5.5
InterfacePWM
Typ. IQ (μA)550
Peak Efficiency93%
Current Accuracy (%)±10%
Current Matching (%)±0.5%
Max. IOUT per/Ch (mA)20
PackageTSOPJW, 12L
Package (mm)3 x 2.85 x 1.02
PackageTSOPJW-12

Features

  • VIN range: 2.7V to 5.5V
  • PWM Brightness Control
  • Tri-mode 1x, 1.5x, and 2x Charge Pump for Maximum Efficiency and VF Coverage
  • Drives Four Low- or High-VF Type LEDs
  • Up to 20mA LED Current per Channel
  • No Inductors
  • 1MHz Switching Frequency
  • Small Application Circuit
  • AutoBias™ Technology
  • IQ < 1A in Shutdown
  • 2.85x3.0mm TSOPJW-12 Package

Product Documents