USB-PD integrated circuit controller and system for powering a dynamic load over a USB type-C cable
A Universal Serial Bus (USB)-Power Delivery (PD) integrated circuit (IC) controller includes: a first control loop configured to calculate a duty cycle based on a difference between a measured operating parameter of a dynamic load and a reference operating parameter; and a second control loop configured to calculate a duty cycle adjustment value that ensures a maximum supported current to be delivered over a USB Type-C cable to the dynamic load is not exceeded during operation of the dynamic load. The USB-PD IC controller is configured to adjust the duty cycle based on the duty cycle adjustment value, and to power the dynamic load over the USB Type-C cable with a DC voltage having a magnitude that corresponds to the adjusted duty cycle. An electronic system that includes the dynamic load and the USB-PD IC controller is also described.
1. An electronic system, comprising:
a dynamic load; and
a Universal Serial Bus (USB)-Power Delivery (PD) integrated circuit (IC) controller comprising:
a first control loop configured to calculate a duty cycle based on a difference between a measured operating parameter of the dynamic load and a reference operating parameter; and
a second control loop configured to calculate a duty cycle adjustment value that ensures a maximum supported current to be delivered over a USB Type-C cable to the dynamic load is not exceeded during operation of the dynamic load,
wherein the USB-PD IC controller is configured to adjust the duty cycle based on the duty cycle adjustment value, and to power the dynamic load over the USB Type-C cable with a DC voltage having a magnitude that corresponds to the adjusted duty cycle.
2. The electronic system of claim 1 , wherein the dynamic load is a DC motor, and wherein the USB-PD IC controller is configured to control each phase of the DC motor.
3. The electronic system of claim 2 , wherein the DC motor is a brushless DC motor.
4. The electronic system of claim 2 , wherein the measured operating parameter is measured rotor velocity of the DC motor and the reference operating parameter is a reference rotor velocity, and wherein the second control loop of the USB-PD IC controller is configured to increase the duty cycle adjustment value as a measured current of the DC motor increases and/or as a rate of change of the measured current increases.
5. The electronic system of claim 4 , wherein the USB-PD IC controller is configured to reduce the duty cycle by the duty cycle adjustment value such that the DC voltage that powers the dynamic load drops below a maximum supported voltage, even if the difference between the measured rotor velocity and the reference rotor velocity widens.
6. The electronic system of claim 1 , wherein the second control loop of the USB-PD IC controller comprises:
a first circuit configured to generate a proportional term that inversely corresponds to a difference between a measured current of the dynamic load and the maximum supported current; and
a second circuit configured to generate a derivative term that inversely corresponds to a rate of change of the difference between the measured current and the maximum supported current.
7. The electronic system of claim 6 , wherein the dynamic load is a brushless DC motor, wherein the measured current is a measured stator current of the brushless DC motor, and wherein the maximum supported current is 5 A.
8. The electronic system of claim 1 , wherein the second control loop of the USB-PD IC controller includes a proportional-derivative (PD) controller for calculating the duty cycle adjustment value, and wherein the first control loop of the USB-PD IC controller includes a proportional-integral (PI) controller or a proportional-integral-derivative (PID) controller for calculating the duty cycle.
9. The electronic system of claim 1 , wherein the dynamic load is a brushless DC motor, and wherein the second control loop of the USB-PD IC controller is configured to increase a DC drive voltage threshold during an open-loop start-up of the brushless DC motor.
10. The electronic system of claim 1 , wherein the second control loop of the USB-PD IC controller is configured to increase the duty cycle adjustment value as a measured current of the dynamic load increases and/or as a rate of change of the measured current increases, and wherein the USB-PD IC controller is configured to reduce the duty cycle by the duty cycle adjustment value such that the DC voltage that powers the dynamic load drops below a maximum supported voltage during closed-loop control of the dynamic load, even if the difference between the measured operating parameter and the reference operating parameter widens.
11. A Universal Serial Bus (USB)-Power Delivery (PD) integrated circuit (IC) controller, comprising:
a first control loop configured to calculate a duty cycle based on a difference between a measured operating parameter of a dynamic load and a reference operating parameter; and
a second control loop configured to calculate a duty cycle adjustment value that ensures a maximum supported current to be delivered over a USB Type-C cable to the dynamic load is not exceeded during operation of the dynamic load,
wherein the USB-PD IC controller is configured to adjust the duty cycle based on the duty cycle adjustment value, and to power the dynamic load over the USB Type-C cable with a DC voltage having a magnitude that corresponds to the adjusted duty cycle.
12. The USB-PD IC controller of claim 11 , wherein the dynamic load is a DC motor, and wherein the USB-PD IC controller is configured to control each phase of the DC motor.
13. The USB-PD IC controller of claim 12 , wherein the DC motor is a brushless DC motor.
14. The USB-PD IC controller of claim 12 , wherein the measured operating parameter is measured rotor velocity of the DC motor and the reference operating parameter is a reference rotor velocity, and wherein the second control loop is configured to increase the duty cycle adjustment value as a measured current of the DC motor increases and/or as a rate of change of the measured current increases.
15. The USB-PD IC controller of claim 14 , wherein the USB-PD IC controller is configured to reduce the duty cycle by the duty cycle adjustment value such that the DC voltage that powers the dynamic load drops below a maximum supported voltage, even if the difference between the measured rotor velocity and the reference rotor velocity widens.
16. The USB-PD IC controller of claim 11 , wherein the second control loop comprises:
a first circuit configured to generate a proportional term that inversely corresponds to a difference between a measured current of the dynamic load and the maximum supported current; and
a second circuit configured to a derivative term that inversely corresponds to a rate of change of the difference between the measured current and the maximum supported current.
17. The USB-PD IC controller of claim 16 , wherein the dynamic load is a brushless DC motor, wherein the measured current is a measured stator current of the brushless DC motor, and wherein the maximum supported current is 5 A.
18. The USB-PD IC controller of claim 11 , wherein the second control loop includes a proportional-derivative (PD) controller for calculating the duty cycle adjustment value, and wherein the first control loop includes a proportional-integral (PI) controller or a proportional-integral-derivative (PID) controller for calculating the duty cycle.
19. The USB-PD IC controller of claim 11 , wherein the dynamic load is a brushless DC motor, and wherein the second control loop of the USB-PD IC controller is configured to increase a DC drive voltage threshold during an open-loop start-up of the brushless DC motor.
20. The USB-PD IC controller of claim 11 , wherein the second control loop is configured to increase the duty cycle adjustment value as a measured current of the dynamic load increases and/or as a rate of change of the measured current increases, and wherein the USB-PD IC controller is configured to reduce the duty cycle by the duty cycle adjustment value such that the DC voltage that powers the dynamic load drops below a maximum supported voltage during closed-loop control of the dynamic load, even if the difference between the measured operating parameter and the reference operating parameter widens.