1A Buck-Boost DC/DC Converter with Programmable Input Current Limit

The LTC3127 is a wide VIN range, highly efficient, 1.35MHz fixed frequency buck-boost DC/DC converter that operates from input voltages above, below or equal to the output voltage. The LTC3127 features programmable average input current limit, making it ideal for power-limited input sources. The input current limit is programmed with a single resistor and is accurate from 0.2A to 1A of average input current.

The topology incorporated provides a continuous transfer function through all operating modes. Other features include <1μA shutdown current, pin-selectable Burst Mode operation and thermal overload protection. The LTC3127 is housed in thermally enhanced 10-lead (3mm × 3mm × 0.75mm) DFN packages and 12-lead MSOP packages.

Applications

* USB Powered GSM Modems

* Supercap Charger

* Handheld Test Instruments

* PC Card Modems

* Wireless Terminals

* Programmable (0.2A to 1A) ±4% Accurate Average Input Current Limit

* Regulated Output with Input Voltages Above, Below or Equal to the Output

* 1.8V to 5.5V (Input) and 1.8V to 5.25V (Output) Voltage Range

* 0.6A Continuous Output Current: VIN > 1.8V

* 1A Continuous Output Current: VIN > 3V

* Single Inductor

* Synchronous Rectification: Up to 96% Efficiency

* Burst Mode® Operation: IQ = 35μA (Pin Selectable)

* Output Disconnect in Shutdown

* <1μA Shutdown Current

* Small, Thermally Enhanced 10-Lead (3mm × 3mm × 0.75mm) DFN and 12-Lead MSOP Packages