US RE43,015 E1Granted

Capacitive high-side switch driver for a power converter

AssigneeSystem General Corp.

InventorTa-yung Yang

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Abstract

The present invention discloses a capacitive high-side switch driver for a power converter. The capacitive high-side switch driver according to the present invention includes an inverter and two alternately conducting totem-pole buffers with complementary duty cycles. The duty cycles alternate in response to an input signal. The capacitive high-side switch driver further includes a low-side transistor and a high-side transistor. Once the low-side transistor is turned on, a bootstrap capacitor is charged to create a floating voltage via a charge-pump diode to supply power for the high-side switch driver. To supply additional power for the high-side switch driver, differential signals are produced to further charge the bootstrap capacitor via a bridge rectifier. The capacitive high-side switch driver utilizes a programmable load to provide variable impedance. Furthermore, an under-voltage protector supervises the supply voltage to ensure a reliable gate driving voltage.

Claims23

Dependent claims

A capacitive high-side switch driver comprising:

an inverter having an input for receiving an input signal;
a first totem-pole buffer and a second totem-pole buffer, wherein said first totem-pole buffer is driven by said input signal and said second totem-pole buffer is driven by an output of said inverter;
a first high-voltage capacitor and a second high-voltage capacitor, wherein the outputs of said first and second totem-pole buffers drive said first and second high-voltage capacitors respectively;
a high-side transistor and a low-side transistor;
a high-side circuit having an output terminal for driving said high-side transistor, wherein said first and second high-voltage capacitors are coupled to an input of said high-side circuit;
a charge-pump diode having an anode supplied with a bias voltage;
a bootstrap capacitor connected in series with said charge-pump diode, wherein said bootstrap capacitor has a negative terminal connected to a source of said high-side transistor, wherein said bootstrap capacitor has a positive terminal connected to a cathode of said charge-pump diode;
and
a bridge rectifier, wherein an input terminal of said bridge rectifier is connected to the input of said high-side circuit, wherein said bridge rectifier is connected in parallel with said bootstrap capacitor.

6 more elements

Dependencies are inferred from the claim text.