Features and Benefits

• 2.7V to 5.5V Input Voltage Range
• No Inductors
• Li-Ion (3.6V) to 1.5V with 81% Efficiency
• Low Noise Constant Frequency Operation
• Output Voltages: 1.5V +-4%, 1.2V +-4%
• Output Current: 250mA
• Shutdown Disconnects Load from VIN
• Low Operating Current: IQ = 35μA
• Low Shutdown Current: ISD <1μA
• Oscillator Frequency = 1.5MHz
• Soft-Start Limits Inrush Current at Turn-On
• Short-Circuit and Overtemperature Protected
• Low Profile (1mm) ThinSOT Package

Product Details

The LTC3250-1.5/LTC3250-1.2 are charge pump step-down DC/DC converters that produce a 1.5V or 1.2V regulated output from a 2.7V to 5.5V input. The parts use switched capacitor fractional conversion to achieve typical efficiency two times higher than that of a linear regulator. No inductors are required.

A unique constant frequency architecture provides a low noise regulated output as well as lower input noise than conventional charge pump regulators.* High frequency operation (fOSC = 1.5MHz) simplifies filtering to further reduce conducted noise. The part also uses Burst Mode? operation to improve efficiency at light loads.

Low operating current (35μA with no load, <1μA in shutdown) and low external parts count (three small ceramic capacitors) make the LTC3250-1.5/LTC3250-1.2 ideally suited for space constrained battery powered applications. The parts are short-circuit and over-temperature protected, and are available in a low profile (1mm) 6-pin ThinSOT?package.

Applications

· Handheld Computers

· Cellular Phones

· Digital Cameras

· Handheld Medical Instruments

· Low Power DSP Supplies