초록 ▼

A gate drive circuit for an isolated gate device, a method of driving the same and a switch-mode power supply employing the circuit or the method. In one embodiment, the circuit includes: (1) a capacitor, having a first terminal coupled to a source of drive voltage and a second terminal coupled to a

A gate drive circuit for an isolated gate device, a method of driving the same and a switch-mode power supply employing the circuit or the method. In one embodiment, the circuit includes: (1) a capacitor, having a first terminal coupled to a source of drive voltage and a second terminal coupled to a gate of the isolated gate device, that stores a charge therein when the drive voltage maintains the isolated gate device in an "on" state and (2) a conductive path, leading from the first terminal to an output terminal of the isolated gate device and enabled when the isolated gate device is to be transitioned from the "on" state to an "off" state, that provides a negative off-bias voltage to the gate thereby to avoid spurious turn-on of the isolated gate device.

대표청구항 ▼

[ What is claimed is:] [1.] A gate drive circuit for an isolated gate device, comprising:a capacitor, having a first terminal coupled to a source of drive voltage and a second terminal coupled to a gate of said isolated gate device, that stores a charge therein when said drive voltage maintains said

[ What is claimed is:] [1.] A gate drive circuit for an isolated gate device, comprising:a capacitor, having a first terminal coupled to a source of drive voltage and a second terminal coupled to a gate of said isolated gate device, that stores a charge therein when said drive voltage maintains said isolated gate device in an "on" state;a conductive path, leading from said first terminal to a terminal of said isolated gate device and enabled when said isolated gate device is to be transitioned from said "on" state to an "off" state, that provides a path for a negative off-bias voltage from said capacitor to discharge a gate capacitance of said gate thereby to avoid spurious turn-on of said isolated gate device;a zener diode, coupled between said second terminal and said terminal of said isolated gate device, that limits a positive value of said drive voltage thereby regulating said negative off-bias voltage; anda blocking diode, serially-coupled in opposition to said zener diode, that prevents said zener diode from conducting when said isolated device is in said "off" state.