Switch mode power converter with adaptive gate voltage regulation for fast turn-off of synchronous rectifier
AssigneeAlpha and Omega Semiconductor International LP
InventorsSitthipong Angkititrakul, Yu Ding, Jian Yin
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Abstract
A power converter incorporating a synchronous rectifier implements adaptive gate voltage regulation for fast turn-off of the synchronous rectifier. In some embodiments, the adaptive gate voltage regulation circuit detects a voltage indicative of a drain current of the synchronous rectifier in each SR conduction cycle and monitors a slope of the detected voltage indicative of a rate of decrease of the drain current of the synchronous rectifier. The adaptive gate voltage regulation circuit further selects a gate discharge current as a function of the slope of the detected voltage to apply to the gate terminal of the synchronous rectifier.
Claims17
A power converter, comprising:
- an input terminal receiving an input voltage and an output terminal providing an output voltage;
- a synchronous rectifier coupled to the output terminal;
- and
- a controller coupled to generate a gate control signal to drive a gate terminal of the synchronous rectifier over a plurality of synchronous rectifier (SR) conduction cycles, the controller comprising an adaptive gate voltage regulation circuit detecting a voltage indicative of a drain current of the synchronous rectifier in each SR conduction cycle and monitoring a slope of the detected voltage indicative of a rate of decrease of the drain current of the synchronous rectifier, the adaptive gate voltage regulation circuit further selecting a gate discharge current as a function of the slope of the detected voltage to apply to the gate terminal of the synchronous rectifier.
Dependencies are inferred from the claim text.