Patent ID: 9379696
Filing Date: 2016-06-28
CPC Classification: H03K

Claim Text:
1. A high voltage bootstrap gate driving apparatus, comprising: a high-end transistor, having a first end, a second end, and a control end, wherein the first end of the high-end transistor receives a first power voltage; a low-end transistor, having a first end, a second end, and a control end, wherein the first end of the low-end transistor is coupled to the second end of the high-end transistor, and the second end of the low-end transistor is coupled to a reference ground voltage; a buffer, providing a high-end driving signal to the control end of the high-end transistor according to a bias voltage, and providing a low-end driving signal to the control end of the low-end transistor; a boost capacitor, serial coupled between a base voltage and the bias voltage, wherein the base voltage is produced at the second end of the high-end transistor; a depletion transistor, having a first end, a second end, and a control end, wherein the first end of the depletion transistor is coupled to a second power voltage, the second end of the depletion transistor is coupled to the bias voltage, and the control end of the depletion transistor receives the reference ground voltage, wherein the buffer, the high-end transistor, the low-end transistor, the boost capacitor and the depletion transistor are disposed in an integrated circuit, wherein as the low-end transistor is conductive according to the low-end driving signal, the high-end transistor is disconnected, and the second power voltage charges the boost capacitor through the depletion transistor, so that the bias voltage is equal to a threshold turn-off voltage of the depletion transistor, wherein when the high-end transistor is conductive according to the high-end driving signal, the low-end transistor is disconnected, and the bias voltage is pulled up to be equal to the first power voltage plus the threshold turn-off voltage.