Dual DC/DC Controller Tracks Outputs In Li-Ion Systems

The LTC3737 is a 2-phase, two channel dc/dc step-down switching regulator with output tracking. It operates with Li-Ion batteries in systems with FPGAs or DSPs requiring power for core and I/O and features a user selectable mode to specify light load operation for highest efficiency (Burst Mode) or lowest supply ripple (pulse skip mode). Over either the maximum range of battery voltage or the minimum voltage differential between input and output, the regulator can operate at up to 100% duty cycle, regulating each output from 0.6V up to a voltage equal to the input supply. The input voltage range is 2.75V to 9.8V. Each channel can drive an external P-channel MOSFET. Switching frequency is programmable up to 750 kHz, allowing the use of smaller surface-mount inductors and capacitors. Other features are a power-good output voltage monitor, a tracking input and internal soft start. The IC is supplied in a low-profile thermally enhanced QFN package or a 24-lead SSOP. It is rated for operation from -40°C to +85°C. Pricing starts at $3.65 each/1,000. LINEAR TECHNOLOGY CORP.,Milpitas, CA. (408) 432-1900, ext. 2593.