LTC1708-PG

The LTC1708 is a dual adjustable 5-bit VID programmable step-down switching regulator controller that drives all N-Channel power MOSFET stages. A constant frequency current mode architecture allows adjustment of the frequency up to 300kHz. Power loss and noise due to the ESR of the input capacitance are minimized by operating the two main controller output stages out of phase.

OPTI-LOOP compensation allows the transient response to be optimized over a wide range of output capacitance and ESR values. The precision 0.8V reference is compatible with future microprocessor generations, and a wide 3.5V to 30V (36V maximum) input supply range that encompasses all battery chemistries. A power good output indicates when the output voltages are within 7.5% of their programmed value.

A RUN/SS pin for each controller provides both soft-start and an optional timed, short-circuit shutdown. Other protection features include: internal foldback current limiting and an output overvoltage crowbar. The forced continuous control pin (FCB) can be used to inhibit BurstMode operation or to regulate a third, flyback output.

Applications

• Notebook and Palmtop Computers, PDAs
• Portable Instruments