Patent ID: 9531373
Filing Date: 2016-12-27
CPC Classification: H02M,H03K

Claim Text:
1. A gate drive circuit for a power transistor, the gate drive circuit comprising: a first switch, a first capacitor, a first terminal of the first capacitor being electrically coupled to the first switch, the first switch being electrically coupled between the first terminal and a voltage supply of the power transistor, a second terminal of the first capacitor being electrically coupled to the reference potential, a first voltage limiter in parallel with the first capacitor for limiting a voltage across the first capacitor to a first predetermined voltage, a second capacitor, a pre-charging circuit arranged between the first terminal of the first capacitor and a first terminal of the second capacitor, a third capacitor, a first terminal of the third capacitor being electrically coupled to a second terminal of the second capacitor, a second terminal of the third capacitor being electrically coupled to a gate terminal of the power transistor, a second switch arranged between the first terminal of the first capacitor and the second terminal of the second capacitor, a third switch arranged between the first terminal of the third capacitor and the reference potential, a fourth switch arranged between the second terminal of the third capacitor and the reference potential, during a setup of the gate drive circuit after applying the voltage supply: the gate drive circuit being configured to arrange the first switch in an on state to electrically couple the supply voltage to the first terminal for charging the first capacitor to obtain the first predetermined voltage across the first capacitor, the gate drive circuit being further configured to configure the pre-charging circuit to pre-charge the second capacitor to obtain a second predetermined voltage across the second capacitor and the gate drive circuit being further configured to pre-charge the third capacitor to obtain a third predetermined voltage across the third capacitor, the gate drive circuit being configured to be powered by the voltage across the first capacitor.