Current ramping during multiphase current regulation

Patent metadata

Field	Value
Publication number	US-9244473-B2
Application number	US-201314144785-A
Country	US
Kind code	B2
Filing date	Dec 31, 2013
Priority date	May 8, 2013
Publication date	Jan 26, 2016
Grant date	Jan 26, 2016

Abstract

Voltage regulators in a current share arrangement may provide a total current to a common load, and may be simultaneously turned on to ramp up member currents. Each voltage regulator may provide a respective member current in the current share configuration. A target current value may be determined from a cycle-averaged current value of the member currents and a voltage error value of the voltage regulator, and each member current may be ramped to the target current value instead of the cycle-averaged current value when the voltage regulators are turned on, resulting in more stable and balanced current ramping. A predictive multi-phase digital controller may therefore operate according to a target current determined based on a measured or inferred inductor current and an error voltage. Pulse-width, pulse position and pulse frequency (adding or skipping pulses) may be calculated according to the operation of the predictive multi-phase digital controller.

First claim

We claim:

1. A method for ramping phase currents in a current share configuration, wherein the phase currents sum to a total current, the method comprising:
providing, by each voltage regulator module of a plurality of voltage regulator modules, a respective phase current in the current share configuration;
determining, for each respective phase current, a target current value according to a cycle-averaged present value of the respective phase current and a voltage error value of the voltage regulator module providing the respective phase current; and
ramping each phase current to the target current value responsive to instructing the plurality of voltage regulator modules to ramp their respective member currents.

2. The method of claim 1 , wherein said determining the target current value according to the voltage error comprises obtaining one or more of:
a proportional control value according to the voltage error;
an integral control value according to the voltage error; or
a derivative control value according to the voltage error.

3. The method of claim 1 , further comprising:
generating, by each voltage regulator module, a common output voltage;
wherein said generating the respective phase current is performed according to the common output voltage.

4. The method of claim 3 , further comprising:
generating, by each voltage regulator module, a respective control pulse;
wherein said generating the common output voltage is performed responsive to the respective control pulse.

5. The method of claim 4 , further comprising determining a width of the control pulse according to:
the target current value at an end of a respective switching cycle; and
a value of the respective phase current at a beginning of the respective switching cycle.

6. The method of claim 4 , further comprising determining a start time of the control pulse, comprising computing a start time that results in delivering a specified amount of charge according to the target current value during the respective switching cycle.

7. The method of claim 6 , wherein the specified amount of charge is commensurate with the target current value multiplied by a time period representative of the respective switching cycle.

8. A voltage regulator module comprising:
an output stage configured to provide a common output voltage together with one or more additional voltage regulator modules, and further configured to provide a corresponding phase current, wherein the corresponding phase current represents a portion of a total current to be provided by a current share configuration established by a plurality of voltage regulator modules, each voltage regulator module of the plurality of voltage regulator modules configured to provide a respective phase current in the current share configuration; and
a controller configured to:
determine a target current value according to a cycle-averaged present value of the corresponding phase current and a voltage error value corresponding to the common output voltage; and
cause the output stage to ramp the phase current to the target current value responsive to the plurality of voltage regulator modules being instructed to ramp their respective phase currents.

9. The voltage regulator module of claim 8 , wherein the controller is further configured to determine the target current value according to one or more of:
a proportional control value based on the voltage error;
an integral control value based on the voltage error; or
a derivative control value based on the voltage error.

10. The voltage regulator module of claim 8 , wherein the controller is further configured to generate a control pulse; and
wherein the output stage is configured to generate and provide the output voltage together with the one or more additional voltage regulator modules, responsive to the control pulse.

11. The voltage regulator module of claim 10 , wherein the controller is further configured to determine a width of the control pulse according to:
the target current value at an end of a respective switching cycle; and
a value of the phase current at a beginning of the respective switching cycle.

12. The voltage regulator module of claim 10 , wherein the controller is further configured to determine a start time of the control pulse that results in delivering a specified amount of charge according to the target current value during the respective switching cycle.

13. The voltage regulator module of claim 12 , wherein the specified amount of charge is commensurate with the target current value multiplied by a time period representative of the respective switching cycle.

14. A predictive multi-phase controller comprising:
an output configured to provide one or more control values usable to generate a control signal that controls an output stage of a voltage regulator module, wherein the voltage regulator module is usable as one of a plurality of voltage regulator modules configured to establish a current share configuration, wherein each voltage regulator module of the plurality of voltage regulator modules is usable to provide a respective phase current in the current share configuration; and
circuitry configured to:
determine a target current value according to a cycle-averaged present value of a first phase current, and a voltage error value corresponding to a common output voltage provided by the plurality of voltage regulator modules, wherein the first phase current is provided by the voltage regulator module; and
ramp the first phase current to the target current value responsive to being instructed to ramp the first phase current, wherein to ramp the first phase current the controller is further configured to adjust one or more of the one or more control values.

15. The predictive multi-phase controller of claim 14 , wherein the circuitry is further configured to determine the target current value according to one or more of:
a proportional control value based on the voltage error;
an integral control value based on the voltage error; or
a derivative control value based on the voltage error.

16. The predictive multi-phase controller of claim 14 , wherein the one or more control values comprise a pulse-width value of a control pulse; and
wherein the control signal comprises the control pulse.

17. The predictive multi-phase controller of claim 16 , wherein the circuitry is further configured to determine the pulse-width value according to:
the target current value at an end of a respective switching cycle; and
a value of the first phase current at a beginning of the respective switching cycle.

18. The predictive multi-phase controller of claim 14 , wherein the one or more control values comprise a start time of a control pulse; and
wherein the control signal comprises the control pulse.

19. The predictive multi-phase controller of claim 18 , wherein the circuitry is further configured to determine the start time of the control pulse that results in delivering a specified amount of charge according to the target current value during a respective switching cycle.

20. The predictive multi-phase controller of claim 19 , wherein the specified amount of charge is commensurate with the target current value multiplied by a time period representative of the respective switching cycle.

21. The predictive multi-phase controller of claim 14 , wherein the circuitry is further configured to determine the target current value according to an estimated value of the first phase current at a begin

Assignees

• Intersil Americas LLC

Inventors

• Young Chris M
• Kidambi Sunder S
• Toker James R

Classifications

• G05F1/12 Primary

  wherein the variable actually regulated by the final control device is AC (G05F1/625 takes precedence) · CPC title

• H02M3/1584

  with a plurality of power processing stages connected in parallel · CPC title

• H02M3/1586

  switched with a phase shift, i.e. interleaved · CPC title