Power Supply With Accurate Energy Measurement

• US 20100020579A1
• Filed: 09/30/2008
• Published: 01/28/2010
• Est. Priority Date: 07/25/2008
• Status: Active Grant

• Current Assignee: Cirrus Logic Incorporated
• Original Assignee: Cirrus Logic Incorporated
• Inventors: Melanson, John L.
• Granted Patent: US 8,330,434 B2
• Time in Patent Office: Days
• US Class Current: 363/89
• CPC Class Codes: H01F 2038/026 non-linear inductive arrangements for converters, e.g. with additional windings
• CPC Class Codes: H01F 3/10 Composite arrangements of magnetic circuits
• CPC Class Codes: H01F 3/14 Constrictions; Gaps, e.g. air-gaps in magnetic shunt paths H01F3/12
• CPC Class Codes: H01F 38/02 for non-linear operation
• CPC Class Codes: H01F 38/08 High-leakage transformers or inductances
• CPC Class Codes: H02M 1/0032 Control circuits allowing low power mode operation, e.g. in standby mode
• CPC Class Codes: H02M 1/42 Circuits or arrangements for compensating for or adjusting power factor in converters or inverters
• CPC Class Codes: Y02B 70/10 Technologies improving the efficiency by using switched-mode power supplies [SMPS], i.e. efficient power electronics conversion e.g. power factor correction or reduction of losses in power supplies or efficient standby modes

Abstract

A power supply includes a rectifier having an AC input and a DC output and a power factor correction (PFC) preregulator, coupled to the rectifier, that increases a power factor of the power supply. The PFC preregulator includes a controller that integrates an input power to determine energy consumption and outputs a signal indicative of the energy consumption.

Claims

1. A power supply, comprising:

a rectifier having an AC input and a DC output; and

a power factor correction (PFC) preregulator, coupled to the rectifier, that increases a power factor of the power supply, wherein the PFC preregulator includes a PFC controller that integrates an input power to determine energy consumption and outputs a signal indicative of the energy consumption.

2. The power supply of claim 1, wherein:

the PFC controller has a non-volatile memory that stores a calibration parameter utilized by the PFC controller to determine the energy consumption.

3. The power supply of claim 1, wherein the PFC controller includes in the calculation of the energy consumption of an input load in the PFC preregulator.

4. The power supply of claim 1, wherein the PFC controller determines a time base for integrating the input power from an AC line frequency.

5. The power supply of claim 1, wherein the signal indicative of the energy consumption indicates average power over a time interval.

6. The power supply of claim 1, wherein the PFC controller determines a power state of the power supply and outputs the signal if the power supply is in a higher power state and refrains from outputting the signal if the power supply is in a lower power state.

7. The power supply of claim 1, and further comprising a DC-to-DC converter coupled to the PFC preregulator.

8. The power supply of claim 1, and further comprising an electromagnetic interference (EMI) filter coupled to the rectifier.

9. A method of operating a power supply, said method comprising:

rectifying an AC input;

applying, by a power factor correction (PFC) preregulator, power factor correction to increase a power factor of the power supply;

determining, by a PFC controller of the PFC preregulator, energy consumption by integrating an input power; and

outputting, by the PFC controller, a signal indicative of the energy consumption.

10. The method of claim 9, and further comprising:

storing a calibration parameter utilized by the controller to determine the energy consumption in a non-volatile memory.

11. The method of claim 9, wherein determining energy consumption includes calculating energy consumption of an input load in the PFC preregulator.

12. The method of claim 9, and further comprising the PFC controller determining from an AC line frequency a time base for integrating the input power.

13. The method of claim 9, wherein outputting a signal indicative of the energy consumption comprises outputting a signal indicating average power over a time interval.

14. The method of claim 9, wherein:

the method further comprises the PFC controller determining a power state of the power supply; and

the outputting comprises the PFC controller outputting the signal if the power supply is in a higher power state and refraining from outputting the signal if the power supply is in a lower power state.

15. A circuit for controlling a power supply, the circuit comprising:

a power factor correction (PFC) controller that controls current flow in a PFC preregulator to increase a power factor of the power supply, wherein the PFC controller integrates an input power to determine energy consumption and outputs a signal indicative of the energy consumption.

16. The circuit of claim 15, wherein:

the PFC controller includes a non-volatile memory that stores a calibration parameter utilized by the PFC controller to determine the energy consumption.

17. The circuit of claim 15, wherein the PFC controller includes in the calculation energy consumption of an input load within the PFC preregulator.

18. The circuit of claim 15, wherein the PFC controller determines a time base for integrating the input power from an AC line frequency.

19. The circuit of claim 15, wherein the signal indicative of the energy consumption indicates average power over a time interval.

20. The circuit of claim 15, wherein the PFC controller determines a power state of the power supply and outputs the signal if the power supply is in a higher power state and refrains from outputting the signal if the power supply is in a lower power state.

21. The circuit of claim 15 wherein the circuit is embodied in an integrated circuit.