High voltage bootstrap gate driving apparatus

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.