Enhanced Product Wide Input Synchronous Buck Controller

The TPS40055 is a family of high-voltage, wide input (8 V to 40 V), synchronous, step-down converters. The TPS40055 family offers design flexibility with a variety of user programmable functions, including soft-start, UVLO, operating frequency, voltage feed-forward, high-side current limit, and loop compensation.

The TPS40055 are also synchronizable to an external supply. The TPS40055 incorporates MOSFET gate drivers for external N-channel high-side and synchronous rectifier (SR) MOSFETs. Gate drive logic incorporates anti-cross conduction circuitry to prevent simultaneous high-side and synchronous rectifier conduction.

The TPS40055 uses voltage feed-forward control techniques to provide good line regulation over the wide (4:1) input voltage range and fast response to input line transients with near constant gain with input variation which eases loop compensation. The externally programmable current limit provides pulse-by-pulse current limit, as well as a hiccup mode operation utilizing an internal fault counter for longer duration overloads.