AAT3194

Pinout




Specifications

• White LED backlighting
• Four (4) outputs
• 20mA full-scale current
• 32-position logarithmic scale with digital control
• Simple Serial Control (S²Cwire) interface
• 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
• V_IN Range: 2.7V to 5.5V
• No inductors
• 600kHz switching frequency
• Iq < 1A in shutdown
• Temperature range: -40 to +85C
• 16-pin QFN, 12-pin TSOPJW package

Description

span id="lblDescription">The AAT3194 is a low noise, constant frequency charge pump DC/DC converters that use fractional (1.5X) conversion to increase efficiency in white LED applications. The device 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 1F flying capacitors and two small bypass capacitors at V_IN and OUT) make the AAT3194 ideally suited for small battery-power applications. AnalogicTech 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 AAT3194 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-current shutdown feature disconnects the load from V_IN and reduces quiescent current to less than 1A. The AAT3194 provides four LED current source outputs. The AAT3194 is available in 16-pin quad QFN package as well as in a 12-pin TSOPJW package