The TPS40074 is a mid voltage, wide input (4.5-V to 28-V), synchronous, step-down controller, offering design flexibility for a variety of user programmable functions, including; soft start, UVLO, operating frequency, voltage feed-forward and high-side FET sensed short circuit protection.
The TPS40074 incorporates MOSFET gate drivers for external N-channel high side and synchronous rectifier (SR) MOSFETs. The gate drive logic incorporates second generation predictive anti-cross conduction circuitry to prevent simultaneous high side and synchronous rectifier conduction, while minimizing to eliminating current flow in the body diode of the SR FET. The TPS40074 allows for starting into pre-biased outputs by not allowing the synchronous rectifier FET to turn on until the commanded voltage during soft start is greater than the existing pre-bias voltage.
The TPS40074 uses voltage feed-forward control techniques to provide good line regulation over a wide input voltage range, and fast response to input line transients. Voltage feed-forward also provides nearly constant power stage gain with input variation to ease loop compensation of wide input range designs. The externally programmable short circuit protection provides fault current limiting, as well as hiccup mode operation for low power dissipationin the presence of a shorted output. The TPS40074 is packaged in a 20-pin QFN package for better thermal performance at higher voltages and frequencies, as well as reduced footprint.
Operation Over 4.5-V to 28-VInput Range
Fixed-Frequency Voltage-Mode Controller
Integrated Unity Gain Amplifier for Remote Output Sensing
Predictive Gate Drive™ Generation II for Improved Efficiency
< 1% Internal 700-mV Reference
Input Voltage Feed Forward Control
Prebiased Output Compatible
Internal Gate Drive Outputs for High-Side and Synchronous N-Channel MOSFETs