AAT3122

High Efficiency 1x/1.5x Fractional Charge Pump for White LED Applications


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

The AAT3122 is a low noise, constant frequency charge pump DC/DC converter that uses a dual mode load switch (1X) and fractional (1.5X) conversion to increase efficiency in white LED applications. With input voltages ranging from 2.7V to 5.5V, the device can produce an output current of up to 120mA. A low external parts count (two 1µF flying capacitors and two small bypass capacitors at VIN and OUT) makes the AAT3122 ideally suited for small battery-powered applications.

AnalogicTech’s Simple Serial Control™ (S²Cwire™) interface is used to enable, disable, and set the LED drive current with a 32-level logarithmic scale LED brightness control. The AAT3122 has a thermal management system to protect the device in the event of a short circuit condition on any of the output pins. Built-in soft-start circuitry prevents excessive inrush current during start-up. High switching frequency enables the use of small external capacitors. A low shutdown current feature disconnects the load from VIN and reduces quiescent current to less than 1µA. The AAT3122 provides a single current source output that can be used to drive up to six LEDs at 20mA each.

The AAT3122 is available in a TSOPJW-12 package.

Please note: AAT3122 is not recommended for new designs.

Specifications

Number of LEDs6
LED Channels1
LED(s) per/Ch6
Min. VIN (V)2.7
Max. VIN (V)5.5
InterfaceS2Cwire™
Typ. IQ (μA)1800
Peak Efficiency93%
Current Accuracy (%)±10%
Current Matching (%)N/A
Max. IOUT per/Ch (mA)132
PackageTSOPJW, 12L
Package (mm)3 x 2.85 x 1.02
PackageTSOPJW-12

Features

  • VIN Range: 2.7V to 5.5V
  • <1µA of shutdown current
  • 1 MHz switching frequency
  • Dual mode 1x and 1.5x charge pump for maximum efficiency
  • Only four (4) external components
  • Simple Serial Control™ (S²Cwire) interface
  • Low noise constant frequency operation
  • 33% less input current than doubler charge pumps
  • Small application circuit
  • Regulated output current
  • Automatic soft-start
  • No inductors
  • TSOPJW-12 package
  • -40°C to +85°C Temperature Range

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