LTC3125 Datasheet | Linear Technology

1.2A Synchronous Step-Up DC/DC Converter with Input Current Limit Features n Programmable Average Input Current Limit n 5% Input Current Accuracy n 200m A to 1000m A Program Range n VIN: 1.8V to 5.5V, VOUT: 2V to 5.25V n Supports High Current GSM/GPRS Load Burst n VIN > VOUT Operation n 1.6MHz Fixed Frequency Operation n Internal Current Sense Resistor n 1.2A Peak Current Limit n Up to 93% Efficiency n Output Disconnect in Shutdown n Soft-Start n Low Quiescent Current Burst Mode® Operation n Available in 2mm × 3mm × 0.75mm DFN Package APPLICATIONS n GSM/GPRS PCMCIA/pact Flash PC Card Modems n Wireless Emergency Locators n Portable Radios n Supercap Chargers DESCRIPTION The LTC®3125 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 500m A and is suitable for a wide variety of applications. In mobile puting, GSM and GPRS cards demand high current pulses well beyond the capability of the PC Card and pact Flash 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 pensated. Output disconnect allows the load to discharge in shutdown, while also providing inrush current limiting. Other Features include a <1μA shutdown current, shortcircuit and thermal overload protection. The LTC3125 is offered in a low profile 0.75mm × 2mm × 3mm package. L, LT, LTC, LTM and Burst Mode are registered trademarks of Linear Technology Corporation. All other trademarks are the property of their respective owners. POWER LOSS (W) TYPICAL APPLICATION PCMCIA/pact Flash (3.3V/500m A Max), 4V GSM Pulsed Load 2.2μH VIN 3.3V 500m A 10μF CER OFF ON CS SW VIN VOUT LTC3125...