System and apparatus for driver circuit for protection of gates of GaN FETs
First Claim
1. An apparatus, comprising:
- a first gallium nitride field effect transistor (GaN FET);
a first driver coupled to a gate of the first GaN FET;
an anode of a capacitor coupled to an output of a driver and a source of the first GaN FET;
a diode having a cathode coupled to the cathode of the capacitor; and
a bootstrap capacitor clamp (BCC) controller, including;
a field effect transistor (FET) coupled to an anode of the diode; and
a comparator coupled to a gate of the FET, the comparator configured to receive as inputs;
a) a signal representative of an input voltage (VDRV) applied to the FET;
b) a ground;
c) a boot signal representative of a voltage at the anode of the capacitor (Boot); and
d) a signal representative of a Voltage at the source of the first GaN FET,wherein the BCC controller is configured to compare;
a) a difference of;
i) the VDRV and the GND, to generate a first comparison signal, tob) a difference of ii) the Boot and the source of the first GaN FET, to generate a second comparison signal;
wherein the BCC controller is further configured to maintain a relationship between the first comparison signal and the second comparison signal base on the comparison, andwherein the BCC controller is further configured to drive a gate output signal to the first GaN FET to maintain this relationship.
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Accused Products
Abstract
A half-bridge power circuit comprises a first gallium nitride field effect transistor (GaN FET); a first driver coupled to a gate of the first GaN FET; an anode of a capacitor coupled to an output of the driver and a source of the first GaN FET; a diode having a cathode coupled to the cathode of the capacitor; and a bootstrap capacitor clamp (BCC) controller, including: a field effect transistor (FET) coupled to an anode of the diode, and a comparator coupled to a gate of the FET, the comparator configured to receive as inputs: a) a signal representative of an input voltage (VDRV) applied to the FET; b) a ground; c) a boot signal representative of a voltage at the anode of the capacitor (Boot); and d) a signal representative of a voltage at the source of the first GaN FET (SW).
53 Citations
23 Claims
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1. An apparatus, comprising:
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a first gallium nitride field effect transistor (GaN FET); a first driver coupled to a gate of the first GaN FET; an anode of a capacitor coupled to an output of a driver and a source of the first GaN FET; a diode having a cathode coupled to the cathode of the capacitor; and a bootstrap capacitor clamp (BCC) controller, including; a field effect transistor (FET) coupled to an anode of the diode; and a comparator coupled to a gate of the FET, the comparator configured to receive as inputs; a) a signal representative of an input voltage (VDRV) applied to the FET; b) a ground; c) a boot signal representative of a voltage at the anode of the capacitor (Boot); and d) a signal representative of a Voltage at the source of the first GaN FET, wherein the BCC controller is configured to compare; a) a difference of;
i) the VDRV and the GND, to generate a first comparison signal, tob) a difference of ii) the Boot and the source of the first GaN FET, to generate a second comparison signal; wherein the BCC controller is further configured to maintain a relationship between the first comparison signal and the second comparison signal base on the comparison, and wherein the BCC controller is further configured to drive a gate output signal to the first GaN FET to maintain this relationship. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8)
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9. A system, comprising:
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a) a GaN FET; b) a bootstrap capacitor clamp (BCC) controller coupled to a source of the GaN FET, the BCC controller comprising; a comparator; a FET, a gate of which is coupled to an output of the comparator; a first isolation switch coupled to a positive input of the comparator, a drain of the first isolation switch coupled between a first resistor and a second resistor, wherein the first resistor is also coupled to an anode of a capacitor, and wherein the second resistor is coupled to a ground; a second isolation switch coupled to a negative input of the comparator, a drain of the second isolation switch coupled between a third resistor and a fourth resistor, wherein the third resistor is also coupled to a signal representative of a signal voltage (VDRV) and wherein the fourth resistor is also coupled to the source of the GaN FET. - View Dependent Claims (10, 11, 12, 13, 14, 15, 16)
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17. A system, comprising:
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a first gallium nitride field effect transistor (GaN FET); a first driver coupled to a gate of the first GaN FET; an anode of a capacitor coupled to an output of a driver and a source of the first GaN FET; a diode having a cathode coupled to the cathode of the capacitor; and a bootstrap capacitor clamp (BCC) controller, including; a field effect transistor (FET) coupled to an anode of the diode; and a comparator coupled to a gate of the FET, the comparator configured to receive as inputs; a) a signal representative of an input voltage (VDRV) applied to the source of the FET; b) a ground; c) a boot signal representative of a voltage at the anode of the capacitor; and d) a signal representative of a voltage at the source of the first GaN FET, wherein the bootstrap capacitor clamp is configured to compare; a) a difference of;
i) the VDRV and the GND to generate a first comparison signal;
tob) a difference of ii) the Boot and the voltage at the source of the first GaN FET to generate a second comparison signal; wherein the BCC controller is configured to maintain a relationship between the first comparison signal and the second comparison signal base on the comparison, and wherein the BCC controller is further configured to drive a gate output signal to the a drain of a second GaN FET coupled to the source of the first GaN FET; an inductor coupled to the source of the first GaN FET; and a drain of the second GaN FET coupled to a source of the first GaN FET. - View Dependent Claims (18, 19, 20, 21, 22, 23)
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Specification