Features and Benefits

  • Programmable Average Input Current Limit
  • 5% Input Current Accuracy
  • 200mA to 1000mA Program Range
  • VIN: 1.8V to 5.5V, VOUT: 2V to 5.25V
  • Supports High Current GSM/GPRS Load Burst
  • VIN > VOUT Operation
  • 1.6MHz Fixed Frequency Operation
  • Internal Current Sense Resistor
  • 1.2A Peak Current Limit
  • Up to 93% Efficiency
  • Output Disconnect in Shutdown
  • Soft-Start
  • Low Quiescent Current Burst Mode® Operation (15μA)
  • Available in 2mm × 3mm × 0.75mm DFN Package

Product Details

The LTC3125 is a high efficiency, synchronous step-up DC/DC converter with an accurate programmable average input current limit. The resistor programmable average input current limit is 5% accurate at 500mA and is suitable for a wide variety of applications. In mobile computing, GSM and GPRS cards demand high current pulses well beyond the capability of the PC Card and CompactFlash slots. The LTC3125 in concert with a reservoir capacitor, keeps the slot power safely within its capabilities providing a high performance and simple solution.

Synchronous rectification produces high efficiency while the 1.6MHz switching frequency minimizes the solution footprint. The current mode PWM design is internally compensated. Output disconnect allows the load to discharge in shutdown, while also providing inrush current limiting.

Other features include a <1μA shutdown current, short circuit and thermal overload protection. The LTC3125 is offered in a low profile 0.75mm × 2mm × 3mm package.


  • GSM/GPRS PCMCIA/CompactFlash PC Card Modems
  • Wireless Emergency Locators
  • Portable Radios
  • Supercap Chargers

Product Lifecycle icon-recommended Recommended for New Designs

This product has been released to the market. The data sheet contains all final specifications and operating conditions. For new designs, ADI recommends utilization of these products.

Evaluation Kits (1)

Tools & Simulations


LTspice® is a powerful, fast and free simulation software, schematic capture and waveform viewer with enhancements and models for improving the simulation of analog circuits.

To launch ready-to-run LTspice demonstration circuits for this part:

Step 1: Download and install LTspice on your computer.

Step 2: Click on the link in the section below to download a demonstration circuit.

Step 3: If LTspice does not automatically open after clicking the link below, you can instead run the simulation by right clicking on the link and selecting “Save Target As.” After saving the file to your computer, start LTspice and open the demonstration circuit by selecting ‘Open’ from the ‘File’ menu.


Models for the following parts are available in LTspice:


Design Resources

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Pricing displayed is based on 1-piece. The USA list pricing shown is for budgetary use only, shown in United States dollars (FOB USA per unit), and is subject to change. International prices may vary due to local duties, taxes, fees and exchange rates.