AAT3134

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 AAT3134 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 maximize efficiency for white LED applications. The device can be used to produce current levels up to 20mA in each of its six outputs to drive LEDs from a 2.7V to 5.5V input. Outputs may be operated individually or paralleled for driving higher-current LEDs. Low external parts counts (two 1µF flying capacitors and two small 1µF capacitors at VIN and OUT) make the AAT3134 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 in two groups of four outputs and two outputs with multiple-level, independently-controlled brightness scales. The AAT3134 has a thermal management system to protect the device in the event of a short circuit condition at the output pin. Built-in soft-start circuitry prevents excessive inrush current during start-up. A high charge pump switching frequency enables 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 AAT3134 is available in a 16-pin quad QFN package.

Please note: AAT3134 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
InterfaceS2Cwire™
Typ. IQ (μA)1800
Peak Efficiency93%
Current Accuracy (%)±10%
Current Matching (%)±0.5%
Max. IOUT per/Ch (mA)20
PackageQFN44, 16L
Package (mm)3 x 3 x 0.9
PackageQFN44-16

Features

  •  

  • VIN range: 2.7V to 5.5V
  • < 1.0µA of shutdown
  • 1 MHz switching frequency
  • Fully independent display lighting
  • Dual mode 1x and 1.5x charge pump for maximum efficiency
  • Drives low-VF and high-VF type LEDs
  • Up to six 20mA outputs
  • Multi-position brightness scale with digital control
  • Low noise constant frequency operation
  • Small application circuit
  • Regulated output current
  • Automatic soft-start
  • No inductors
  • 16-pin QFN package
  • -40 to +85°C temperature range

     

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