Soochow University

Daqian Zhang

Bowen Zhong

Lining Sun

This invention relates to a self-excited oscillation suppression device and method for the power amplifying circuit, belonging to the field of electronic technology. Said power amplifying circuit includes a FET and a feedback loop. Said device includes: a first compensation circuit which is connected between a drain and a gate of the FET and a second compensation circuit which is connected in parallel with a feedback resistor of said feedback loop. It can solve self-excited oscillation caused by deep negative feedback in the existing power amplifying circuit. The first compensation circuit can shift the open-loop gain curve forward as a whole, and the second compensation circuit can speed up the closure of the feedback gain curve and the open-loop gain curve so that the two curves will close up before the self-excited oscillation; the self-excited oscillation will be suppressed, and the stability of the power amplifying circuit will be improved.

Self-excited oscillation suppression device and method for the power amplifying circuit

A method and device for adjusting the switching speed of a MOSFET are disclosed. The MOSFET is connected to drive switch, the collector of the drive switch is connected to the grid of the MOSFET through the grid resistor, the emitter of the drive switch is grounded through the emitter resistor, and the collector of the drive switch is also connected to the source resistor through the collector resistor, the other end of the source resistor is connected to the source of the MOSFET; the drain of the MOSFET is connected to the current source. The method comprises: obtaining the adjustment target of the switching speed for the MOSFET, determining the first resistance value of the emitter resistor and/or the second resistance value of the collector resistor based on said adjustment target, controlling the operation of the MOSFET according to the adjusted resistance value.

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Suzhou, China

Daqian Zhang