描述 Description

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

The AAT3113/4 are low noise, constant frequency charge pump DC/DC converters that use fractional (1.5X) conversion to increase efficiency in white LED applications. The devices can be used to produce current levels up to 20mA for each output from a 2.7V to 5.5V input. Low external parts counts (two 1°F flying capacitors and two small bypass capacitors at VIN and OUT) make the AAT3113/4 ideally suited for small battery-power applications.

AnalogicTech’s Simple Serial Control? (S2Cwire?) interface is used to enable, disable, and set the LED drive current for a 32-level logarithmic scale LED brightness control. The AAT3113/4 have 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-current shutdown feature disconnects the load from VIN and reduces quiescent current to less than 1μA. The AAT3113 provides four LED current source outputs, and the AAT3114 provides six.

The AAT3113/4 are available in 16-pin quad QFN packages; the AAT3113 is also available in a 12-pin TSOPJW package.

特性 Features

? AAT3113 – Four (4) outputs
? AAT3114 – Six (6) outputs
? 20mA full-scale current
? Simple Serial Control? (S2Cwire?) interface
? 32-position logarithmic scale with digital control
? Low noise constant frequency operation
? 33% less input current than Doubler?Charge Pump
? High accuracy brightness matching
? Small application circuit
? Regulated output current
? Automatic soft-start
? VIN Range: 2.7V to 5.5V
? No inductors
? 600kHz switching frequency
? IQ < 1μA in shutdown
? Temperature range: -40 to +85°C
? 16-pin QFN, 12-pin TSOPJW package