LTC3250 High Efficiency, Low Noise, Inductorless Step-Down DC/DC Converter

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.


  • Handheld Computers
  • Cellular Phones
  • Digital Cameras
  • Handheld Medical Instruments

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