描述 Description

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

The AAT3131 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 three of its outputs, and 30mA in one of its 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 AAT3131 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: the three 20mA outputs and the single 30mA output with multiple level logarithmic scales. The AAT3131 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 AAT3131 is available in very small 12-pin TSOPJW package.

Please note: AAT3131 is not recommended for new designs.

特性 Features

? VIN Range: 2.7V to 5.5V
? < 1.0μA of shutdown current
? 1MHz switching frequency
? White LED backlighting
? 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 three 20mA outputs
? Single 30mA output
? Multi-position logarithmic scale with digital control
? Low noise constant frequency operation
? Regulated output current
? Automatic soft-start
? No inductors
? -40 to +85°C temperature range
? 12-pin TSOPJW package