LTC3125 - 1.2A Synchronous Step-Up DC/DC Converter with Input Current Limit

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.

Features
  • 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
Typical Application

Applications
  • GSM/GPRS PCMCIA/CompactFlash PC Card Modems
  • Wireless Emergency Locators
  • Portable Radios
  • Supercap Chargers
Packaging
Order Information
Part NumberPackageTempPrice(1-99)Price (1k)*
LTC3125EDCB#PBF2x3 DFN-8E$3.22
LTC3125EDCB#TRMPBF2x3 DFN-8E$3.22$2.30
LTC3125EDCB#TRPBF2x3 DFN-8E$3.22$2.25
Demo Boards
Part NumberDescriptionPrice
DC1267ALTC3125EDCB Demo Board | 1.5A Switch, 3.3V Input, Vout = 4V @ 500mA (2A Pulses)$150.00
Datasheet
Reliability Data
LT Journal
Press Release
LTspice
Related Product
LTC3125 - 1.2A Synchronous Step-Up DC/DC Converter with Input Current Limit
R415 - Reliability Data
June 2008 - Compact Power Solution Overcomes Peak Power Limitations in PCMCIABased Pulsed-Load GSM and GPRS Applications
LTC3125 - 1.2A、1.6MHz 同步升压型稳压器提供输出断接和可编程输入电流限制
LTC3125 Footprints and Symbols
LTC3125 Demo Circuit - Step-Up DC/DC Converter with Input Current Limit (3.0-3.6V to 4V@2A Pulsed Load)