SWITCH STATE CONTROLLER WITH A SENSE CURRENT GENERATED OPERATING VOLTAGE

• US 20090189579A1
• Filed: 06/30/2008
• Published: 07/30/2009
• Est. Priority Date: 01/30/2008
• Status: Active Grant

• Current Assignee: Cirrus Logic Incorporated
• Original Assignee: Cirrus Logic Incorporated
• Inventors: Melanson, John L., Thompson, Karl, Gaetano, Mauro, Nanda, Kartik
• Granted Patent: US 8,576,589 B2
• Time in Patent Office: Days
• US Class Current: 323/282
• CPC Class Codes: H02J 2207/20 Charging or discharging characterised by the power electronics converter
• CPC Class Codes: H02J 7/342 The other DC source being a battery actively interacting with the first one, i.e. battery to battery charging with circuits for polarity protection H02J7/0034
• CPC Class Codes: H02M 3/33592 having a synchronous rectifier circuit or a synchronous freewheeling circuit at the secondary side of an isolation transformer
• CPC Class Codes: Y02B 40/00 Technologies aiming at improving the efficiency of home appliances, e.g. induction cooking or efficient technologies for refrigerators, freezers or dish washers
• 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 system and method includes a switch state controller that is operational to control a switching power converter during certain power loss conditions that cause conventional switch state controllers to have diminished or no functionality. In at least one embodiment, during certain power loss conditions, such as when an auxiliary power supply is in standby mode or when the switching power converter is not operating, a power supply for the switch state controller does not provide sufficient operating power to the switch state controller during certain power loss conditions. In at least one embodiment, during such power loss conditions power is generated for the switch state controller using sense input and/or sense output currents of the switching power converter to allow an integrated circuit (IC) switch state controller to generate a control signal to control a switch of the switching power converter.

Claims

1. An apparatus comprising:

a controller, wherein the controller is configured to;

operate during at least one controller operational mode from an operating voltage generated from at least a first portion of the first sense current, wherein the first sense current is resistively derived from a first voltage sense of a switching power converter;

receive at least a second portion of the first sense current; and

use the second portion of the first sense current to control a switching operation of the switching power converter.

2. The apparatus of claim 1 wherein the switching operation of the switching power converter is a member of a group consisting of:

(i) operating a switch of the switching power converter to provide power factor correction and (ii) operating the switch of the switching power converter to regulate an output voltage of the switching power converter.

3. The apparatus of claim 1 wherein the controller is configured to operate from the operating voltage generated from at least the first portion of the first sense current when a primary auxiliary power supply provides insufficient power to allow the controller to at least control an output voltage of the switching power converter.

4. The apparatus of claim 1 wherein the first sense current is resistively derived from at least one of one of:

(i) an input voltage to the switching power converter and (ii) an output voltage of the switching power converter.

5. The apparatus of claim 1 wherein the controller is further configured to cause the switching power converter to generate an approximately constant output voltage when the controller operates from the operating voltage generated from at least the first portion of the first sense current.

6. The apparatus of claim 1 wherein the controller is further configured to use at least the second portion of the first sense current to control at least one of (i) power factor correction of the switching power converter and (ii) regulation of an output voltage of the switching power converter.

7. The apparatus of claim 1 wherein the at least one controller operational mode comprises a start-up-mode of the controller.

8. The apparatus of claim 1 further comprising:

a secondary auxiliary power supply having a first input to receive at least the second portion of the first sense current, wherein the secondary auxiliary power supply system is configured to generate the operating voltage from at least the second portion of the first sense current.

9. The apparatus of claim 8 wherein the secondary auxiliary power supply and the controller comprise components included in an integrated circuit.

10. The apparatus of claim 1 wherein the controller is configured to operate from an operating voltage derived from at least the first sense current and a second sense current, wherein the second sense current is resistively derived from a second voltage sense of the switching power converter.

11. The apparatus of claim 10 wherein the first sense current senses an input voltage to the switching power converter and the second sense current senses an output voltage of the switching power converter.

12. The apparatus of claim 10 wherein the controller includes a first converter to convert the first portion of the first sense current into data representing the input voltage to the switching power converter and a second converter to convert a second portion of the second sense current into data representing the output voltage of the switching power converter, wherein the apparatus further comprises:

a secondary auxiliary power supply, and the secondary auxiliary power supply comprises;

a first sense current proportional divider circuit coupled to the controller to provide the first portion of the first sense current to the first converter for sensing the input voltage of the switching power converter; and

a second sense current proportional divider circuit coupled to the controller to provide the second portion of the second sense current to the second converter for sensing the output voltage of the switching power converter;

wherein the first and second proportional divider circuits are configured to generate the operating voltage from the first portion of the first sense current and the second portion of the second sense current.

13. The apparatus of claim 10 the controller comprises:

a first converter to convert the second portion of the first sense current into data representing the input voltage of the switching power converter; and

a second converter to convert a second portion of the second sense current into data representing the output voltage of the switching power converter; and

the apparatus further comprises a secondary auxiliary power supply, and the second auxiliary apparatus comprises;

first circuitry coupled to the controller to provide the first sense current to the first converter for sensing the input voltage of the switching power converter and to at least contribute to generation of the operating voltage for the controller during non-overlapping periods of time; and

second circuitry coupled to the controller to provide the second sense current to the second converter for sensing the output voltage of the switching power converter and to at least contribute to generation of the operating voltage for the controller during non-overlapping periods of time.

14. The apparatus of claim 1 further comprising:

a secondary auxiliary power supply having a first input to receive at least the second portion of the first sense current and a second portion of a second sense current, wherein the second sense current is resistively derived from a second voltage sense of the switching power converter and the secondary auxiliary power supply system is configured to generate the operating voltage from at least the second portions of the first and second sense currents.

15. The apparatus of claim 14 further comprising:

a first resistive circuit, coupled between the input of the switching power converter and the second auxiliary power supply, to provide resistance to the first sense current; and

a second resistive circuit, coupled between an output of the switching power converter and the second auxiliary power supply, to provide resistance to the second sense current.

16. The apparatus of claim 15 wherein the second resistive circuit has a greater resistance than the first resistive circuit.

17. The apparatus of claim 1 wherein the first sense current is a member of a group consisting of:

a sense current derived from an input voltage to the switching power converter and a sense current derived from the output voltage of the switching power converter.

18. The apparatus of claim 1 further comprising the switching power converter, wherein the switching power converter is coupled to the controller.

19. The apparatus of claim 18 wherein the switching power converter is a member of a group consisting of:

a boost converter and a buck converter.

20. A method comprising:

operating the controller during at least one controller operational mode from an operating voltage generated from at least a first portion of the first sense current, wherein the first sense current is resistively derived from a first voltage sense of a switching power converter;

receiving in a controller at least a second portion of the first sense current; and

using the second portion of the first sense current to control a switching operation of the switching power converter.

21. The method of claim 20 wherein the switching operation of the switching power converter is a member of a group consisting of:

operating a switch of the switching power converter to provide power factor correction and operating the switch of the switching power converter to regulate an output voltage of the switching power converter.

22. The method of claim 20 further comprising:

operating the controller to cause the switching power converter to generate an approximately constant output voltage when the controller operates from the operating voltage generated from at least the first portion of the first sense current.

23. The method of claim 20 wherein the first sense current is resistively derived from at least one of one of:

(i) an input voltage to the switching power converter and (ii) an output voltage of the switching power converter.

24. The method of claim 20 operating the controller further comprises:

operating the controller from the operating voltage generated from at least the first portion of the first sense current when a primary auxiliary power supply provides insufficient power to allow the controller to at least control an output voltage of the switching power converter.

25. The method of claim 24 wherein the primary auxiliary power supply provides insufficient power to allow the controller to at least control an output voltage of the switching power converter during standby-mode of the power supply system.

26. The method of claim 20 wherein operating the controller further comprises:

operating the controller during at least one controller operational mode from an operating voltage generated from at least a first portion of the first sense current and a first portion of a second sense current, wherein the second sense current is resistively derived from a second voltage sense of a switching power converter.

27. The method of claim 26 wherein operating the controller from the operating voltage generated from the first and second sense currents comprises operating the controller from the operating voltage generated from the first sense current and from a second sense current at least when a primary auxiliary power supply provides insufficient power to allow the controller to at least control an output voltage of the switching power converter.

28. The method of claim 26 further comprising:

providing the first sense current to the first converter for sensing the input voltage of the switching power converter and to at least contribute to generation of the operating voltage for the controller during non-overlapping periods of time; and

providing the second sense current to the second converter for sensing the output voltage of the switching power converter and to at least contribute to generation of the operating voltage for the controller during non-overlapping periods of time.

29. The method of claim 26 wherein the first sense current has a greater magnitude than the second sense current.

30. The method of claim 26 further comprising:

providing a second portion of the first sense current to a first converter for sensing the input voltage of the switching power converter while providing a first portion of the first sense current to a secondary auxiliary power supply system for generating the operating voltage.

31. The method of claim 26 wherein the first sense current is a member of a group consisting of:

a sense current derived from an input voltage to the switching power converter and a sense current derived from the output voltage of the switching power converter.

32. The method of claim 20 further comprising:

determining a switch control signal to control a switch of the switching power converter, wherein the switch controls input current to the switching power converter.

33. An apparatus comprising:

means for operating the controller during at least one controller operational mode from an operating voltage generated from at least a first portion of the first sense current, wherein the first sense current is resistively derived from a first voltage sense of a switching power converter;

means for receiving in a controller at least a second portion of the first sense current; and

means for using the second portion of the first sense current to control a switching operation of the switching power converter.