System and methods for motor drive using GAN synchronous rectification

Patent metadata

Field	Value
Publication number	US-12438535-B2
Application number	US-202318189123-A
Country	US
Kind code	B2
Filing date	Mar 23, 2023
Priority date	Mar 24, 2022
Publication date	Oct 7, 2025
Grant date	Oct 7, 2025

Abstract

Systems and methods for a GaN-based motor drive circuit using synchronous rectification is disclosed. In one aspect, a method of operating a motor drive circuit includes providing a half-bridge circuit including a high-side GaN switch and a low-side GaN switch coupled in series at an output node, providing a motor coupled to the output node, turning on the high-side GaN switch such that a first current flows through the motor, turning off the high-side GaN switch, turning on the low-side GaN switch when a voltage at the output node drops below a predetermined threshold voltage, sensing, using a sense device coupled to the low-side GaN switch, a magnitude of a second current that flows through the low-side GaN switch, and turning off the low-side GaN switch when the magnitude of the second current drops below a predetermined threshold current.

First claim

What is claimed is:

1. A method of operating a motor drive circuit, the method comprising:
providing a half-bridge circuit including:
a high-side gallium nitride (GaN) switch having a first gate terminal, a first drain terminal and a first source terminal; and
a low-side GaN switch having a second gate terminal, a second drain terminal and a second source terminal, wherein the first drain terminal is coupled to a power supply, the first source terminal is coupled to the second drain terminal at an output node and the second source terminal is coupled to a ground;

providing a motor coupled to the output node;
turning on the high-side GaN switch such that a first current flows through the motor;
turning off the high-side GaN switch;
turning on the low-side GaN switch when a voltage between the second drain terminal and the second source terminal drops below a predetermined threshold voltage;
sensing, using a sense device coupled to the low-side GaN switch, a magnitude of a second current that flows through the low-side GaN switch; and
turning off the low-side GaN switch when the magnitude of the second current drops below a predetermined threshold current.

2. The method of claim 1 , wherein turning on the low-side GaN switch is performed within a predetermined period of time after a control signal that controls a conductivity state of the high-side GaN switch goes high.

3. The method of claim 1 , further comprising turning off the low-side GaN switch prior to turning on the high-side GaN switch if a control signal that controls a conductivity state of the high-side GaN switch goes high after the low-side GaN switch is turned on.

4. The method of claim 1 , wherein the predetermined threshold current has a value that is 10% of a rated current of the low-side GaN switch.

5. The method of claim 1 , wherein the predetermined threshold voltage is a first predetermined threshold voltage, and wherein the method of claim 1 further comprises transmitting an arming signal to the low-side GaN switch when the voltage between the second drain terminal and the second source terminal exceeds a second predetermined threshold voltage, and wherein the arming signal goes low prior to the low-side GaN switch turning on.

6. The method of claim 5 , wherein a value of the first predetermined threshold voltage is −1.0 V, and wherein a value of the second predetermined threshold voltage is 12.0 V.

7. The method of claim 1 , wherein the half-bridge circuit is a first half-bridge circuit and the output node is a first output node, and wherein the method of claim 1 further comprises a second half-bridge circuit having a second output node, wherein the motor is coupled between the first output node and the second output node.

8. A circuit comprising:
a high-side gallium nitride (GaN) switch having a first gate terminal, a first drain terminal and a first source terminal;
a low-side GaN switch having a second gate terminal, a second drain terminal and a second source terminal, wherein the first drain terminal is coupled to a power supply, the first source terminal is coupled to the second drain terminal at an output node and the second source terminal is coupled to a ground;
a drive circuit coupled to the high-side GaN switch and to the low-side GaN switch; and
a sense device coupled to the low-side GaN switch and arranged to sense a magnitude of a current that flows through the low-side GaN switch;
wherein the drive circuit is arranged to:
turn on the high-side GaN switch when a control signal that controls a conductivity state of the high-side GaN switch goes high;
turning off the high-side GaN switch when the control signal goes low;
turn on the low-side GaN switch when a voltage between the second drain terminal and the second source terminal drops below a predetermined threshold voltage; and
turn off the low-side GaN switch when the magnitude of the current drops below a predetermined threshold current.

9. The circuit of claim 8 , wherein the drive circuit is further arranged to turn on the low-side GaN switch within a predetermined period of time after the control signal goes high.

10. The circuit of claim 8 , wherein the drive circuit is further arranged to turn off the low-side GaN switch prior to turning on the high-side GaN switch if the control signal goes high after the low-side GaN switch is turned on.

11. The circuit of claim 8 , wherein the predetermined threshold current has a value that is 10% of a rated current of the low-side GaN switch.

12. The circuit of claim 8 , wherein the predetermined threshold voltage is a first predetermined threshold voltage, and wherein the drive circuit is further arranged to transmit an arming signal to the low-side GaN switch when the voltage between the second drain terminal and the second source terminal exceeds a second predetermined threshold voltage, and to set the arming signal to a low state prior to the low-side GaN switch turning on.

13. The circuit of claim 8 , wherein the drive circuit is formed in silicon.

14. A method of operating a motor drive circuit, the method comprising:
providing a half-bridge circuit including:
a high-side gallium nitride (GaN) switch having a first gate terminal, a first drain terminal and a first source terminal; and
a low-side GaN switch having a second gate terminal, a second drain terminal and a second source terminal, wherein the first drain terminal is coupled to a power supply, the first source terminal is coupled to the second drain terminal at an output node and the second source terminal is coupled to a ground;

providing a motor coupled to the output node;
turning on the high-side GaN switch such that a first current flows through the motor;
turning off the high-side GaN switch;
turning on the low-side GaN switch when a voltage between the second drain terminal and the second source terminal drops below a predetermined threshold voltage; and
turning off the low-side GaN switch when the voltage between the second drain terminal and the second source terminal exceeds the predetermined threshold voltage.

15. The method of claim 14 , wherein turning on the low-side GaN switch is performed within a predetermined period of time after a control signal that controls a conductivity state of the high-side GaN switch goes high.

16. The method of claim 14 , further comprising turning off the low-side GaN switch prior to turning on the high-side GaN switch if a control signal that controls a conductivity state of the high-side GaN switch goes high after the low-side GaN switch is turned on.

17. The method of claim 14 , wherein the predetermined threshold voltage is a first predetermined threshold voltage, and wherein the method of claim 1 further comprises transmitting an arming signal to the low-side GaN switch when the voltage between the second drain terminal and the second source terminal exceeds a second predetermined threshold voltage, and wherein the arming signal goes low prior to the low-side GaN switch turning on.

18. The method of claim 17 , wherein a value of the first predetermined threshold voltage is −1.0 V, and wherein a value of the second predetermined threshold voltage is 12.0 V.

19. The method of claim 14 , further comprising providing a drive circuit coupled to the high-side GaN switch and to the low-side GaN switch.

20. The method of claim 19 , wherein the drive circuit includes a comparator arranged to detect the voltage between the second drain terminal and the second source terminal.

Assignees

• Navitas Semiconductor Ltd

Inventors

• Sharma Santosh
• Ribarich Thomas
• Uccelli Matteo
• Sinow Victor

Classifications

• H03K17/063

  in field-effect transistor switches · CPC title

• H03K2217/0063

  High side switches, i.e. the higher potential [DC] or life wire [AC] being directly connected to the switch and not via the load · CPC title

• H03K2217/0072

  Low side switches, i.e. the lower potential [DC] or neutral wire [AC] being directly connected to the switch and not via the load · CPC title

• H03K17/165

  by feedback from the output circuit to the control circuit · CPC title

• H03K17/04206

  in field-effect transistor switches · CPC title