The LTC1625IGN#PBF is a synchronous step-down Switching Regulator Controller that drives external N-channel power MOSFETs using few external components. current-mode control with MOSFET VDS sensing eliminates the need for a sense resistor and improves efficiency. The frequency of a nominal 150kHz internal oscillator can be synchronized to an external clock over a 1.5:1 frequency range. Burst Mode operation at low load currents reduces switching losses and low dropout operation extends operating time in battery-powered systems. A forced continuous mode control pin can assist secondary winding regulation by disabling Burst Mode operation when the main output is lightly loaded. Fault protection is provided by foldback current limiting and an output overvoltage comparator. An external capacitor attached to the RUN/SS pin provides soft start capability for supply sequencing.
● Highest efficiency current mode controller
● No sense resistor required
● Stable high current operation
● Dual N-channel MOSFET synchronous drive
● ±1% 1.19V Reference
● Programmable fixed frequency with injection lock
● 99% Duty cycle very low drop out operation
● Forced continuous mode control pin
● Optional programmable soft start
● Pin selectable output voltage
● Foldback current limit
● Output overvoltage protection
● <30µA Logic controlled micropower shutdown
