Patent ID: 9590621
Date: 2017-03-07
CPC Classifications: H03K

Claim:
1. A gate drive circuit for controlling the operation of a first semiconductor switch having a gate, the isolated gate drive circuit comprising: a first transformer that transfers a first pulse from a primary side of the first transformer to a secondary side of the first transformer; a first rectifier for providing the transferred first pulse directly to the gate of the first semiconductor switch to cause the semiconductor switch to be turned on; a second semiconductor switch, which, in a first state, clamps a gate voltage of the first semiconductor switch, and, in a second state, is open; a reset circuit that is triggered by the arrival of the first pulse to place the second semiconductor switch in the second state upon an arrival of the first pulse, wherein the reset circuit includes a timer responsive to the arrival of the first pulse, and wherein the reset circuit is configured to turn off the semiconductor switch within a predefined interval after the arrival of the first pulse; and a second transformer that transfers a second pulse from a primary side of the second transformer to the secondary side of the second transformer, wherein the reset circuit is configured to turn off the first semiconductor switch in response to the arrival of the second pulse irrespective of whether the predefined interval has expired.