| 摘要 |
An active clamp circuit for avalanching and clamping voltage at a gate terminal of a first transistor connected to a power source. The active clamp circuit includes a second transistor for turning ON the first transistor; a third transistor having EPI breakdown voltage less than that of the first transistor; a resistor coupled between a node and source and gate terminals of the third transistor; and an amplifier for comparing voltage on the resistor to a reference voltage and providing an output signal to control the second transistor, wherein, when the third transistor avalanches and the voltage across the resistor exceeds the reference voltage, the output signal turns ON the second transistor thereby clamping the gate terminal of the first transistor, wherein the active clamp circuit tracks the channel characteristic of the first transistor. |
