1.5A, 3MHz Synchronous Step-Up DC/DC Converter with Output Disconnect

The LTC3422 is a high efficiency, current mode, fixed frequency, step-up DC/DC converter with true output disconnect and inrush current limiting. The part is guaranteed to start up from an input voltage of 1V. The device includes a 0.20Ω N-channel MOSFET switch and a 0.24Ω P-channel MOSFET synchronous rectifier. The output voltage, switching frequency, soft-start time, Burst Mode threshold and loop compensation are all simply programmed using tiny external passive components.

Quiescent current is only 25μA during Burst Mode operation, maximizing battery life in portable applications. The oscillator frequency can be programmed up to 3MHz and can be synchronized to an external clock applied to the SYNC pin.

Other features include 1μA shutdown, short-circuit protection, anti-ringing control, thermal shutdown and current limit. The LTC3422 is available in a (3mm × 3mm × 0.75mm) 10-pin DFN package.

Applications

* Wireless Handsets

* Handheld Computers

* GPS Receivers

* MP3 Players

* 700mA Continuous/1A Pulsed Output Current for Li-Ion to 5V Applications

* Synchronous Rectification: Up to 96% Efficiency

* True Output Disconnect

* Inrush Current Limiting

* Adjustable Automatic Burst Mode® Operation

* Low Noise, Fixed Frequency Operation from 100kHz to 3MHz

* 0.5V to 4.5V Input Range

* 2.25V to 5.25V Adjustable Output Voltage

* Guaranteed 1V Start-Up

* Programmable Soft-Start

* Synchronizable Oscillator

* Low Quiescent Current: 25μA

* <1μA Shutdown Current

* Anti-Ringing Control

* Small (3mm × 3mm × 0.75mm) Thermally Enhanced 10-Pin DFN Package