On-board power supply protection

• US 9,041,244 B2
• Filed: 12/30/2010
• Issued: 05/26/2015
• Est. Priority Date: 12/30/2010
• Status: Active Grant

• Current Assignee: Infineon Technologies AG
• Original Assignee: Infineon Technologies AG
• Inventors: Graf, Alfons
• Primary Examiner(s): Fureman, Jared
• Assistant Examiner(s): Pham, Duc M
• Application Number:
  US12/982,613
• Publication Number:
  US 20120169116A1
• Time in Patent Office: 1,608 Days
• Field of Search: 307/10.7
• US Class Current: 307/10.7
• CPC Class Codes: B60R 16/03 for supply of electrical power to vehicle subsystems or for circuit arrangements for charging batteries H02J7/00
• CPC Class Codes: H02J 7/0034 using reverse polarity correcting or protecting circuits mechanical means of polarity protection H02J7/0045

Abstract

The system includes a first and a second power supply terminal configured to have at least one of a battery and a generator connected thereto, a first external terminal coupled to the first power supply terminal, and a second external terminal coupled to the second power supply terminal, and a protection unit connected between the first external terminal and the first power supply terminal. The protection unit includes a semiconductor switching unit having a load path and a control terminal, the load path connected between the first external terminal and the first power supply terminal, and a control circuit coupled to the control terminal of the semiconductor switching unit and configured to switch the switching unit on and off dependent on at least one electrical parameter in the on-board power supply system.

Claims

1. An on-board power supply system, the system comprising:

a first power supply terminal and a second power supply terminal configured to have a battery and/or a generator connected thereto, wherein the power supply system is configured to have a first electrical polarity applied to the first and second power supply terminals;

a first external terminal coupled to the first power supply terminal and a second external terminal coupled to the second power supply terminal; and

a protection unit connected between the first external terminal and the first power supply terminal,

wherein the protection unit comprises;

a semiconductor switching unit having a load path and a control terminal, the load path connected between the first external terminal and the first power supply terminal; and

a control circuit coupled to the control terminal of the semiconductor switching unit and configured to switch the semiconductor switching unit on and off dependent on at least one electrical parameter in the on-board power supply system, wherein

the control circuit is configured to turn the semiconductor switching unit off when the at least one electrical parameter indicates that an electrical polarity applied to the first and second external terminals is opposite the first electrical polarity,

the first electrical polarity is supplied to the first and second power supply terminals and the battery and/or the generator connected thereto when the semiconductor switching unit is turned off, and

the at least one electrical parameter comprises a first voltage between the first and second external terminals, wherein the control circuit is configured to switch the semiconductor switching unit on and off dependent on the first voltage between the external terminals and dependent on a second voltage across the protection unit.

2. The on-board power supply system of claim 1, wherein the at least one electrical parameter comprises a second voltage across the protection unit.

3. The on-board power supply system of claim 1, wherein the at least one electrical parameter comprises a current through the protection unit.

4. The on-board power supply system of claim 1 wherein the control circuit is configured to switch the semiconductor switching unit on when the first voltage is higher than a first threshold value and when the second voltage is outside a given first voltage range.

5. The on-board power supply system of claim 4, wherein the first threshold value is a voltage between about −

5V and about −

0.05V.

6. The on-board power supply system of claim 4, wherein the first voltage range includes zero.

7. The on-board power supply system of claim 4, wherein the first voltage range ranges from between about −

5V and about −

0.05V to between about 0.05V and about 1.0V.

8. The on-board power supply system of claim 4, wherein the first voltage range is symmetrical relative to zero.

9. The on-board power supply system of claim 4, wherein the first voltage range is asymmetrical relative to zero.

10. The on-board power supply system of claim 1 further comprising:

a switch operated by an ignition switch, and wherein the control circuit is further configured to switch the switching unit on and off dependent on a switching state of the switch.

11. The on-board power supply system of claim 1, wherein the semiconductor switching unit comprises at least one semiconductor switching element.

12. The on-board power supply system of claim 11, wherein the semiconductor switching unit comprises at least two semiconductor switching elements connected in parallel.

13. The on-board power supply system of claim 11, wherein the semiconductor switching unit comprises one of an n-type MOSFET, a p-type MOSFET, an IGBT or a BJT.

14. The on-board power supply system of claim 1, wherein the protection unit further comprises a resistive element connected between the first external terminal and the first power supply terminal.

15. The on-board power supply system of claim 14, wherein the resistive element comprises an ohmic resistor, a PTC resistor, a switching element, or a constant current source.

16. The on-board power supply system of claim 14, wherein the control circuit is configured to switch the semiconductor switching unit on and off dependent on a first voltage between the external terminals and dependent on a current through the protection unit.

17. The on-board power supply system of claim 16, wherein the control circuit is configured to switch the semiconductor switching unit on when the first voltage is higher than a first threshold value and when the current through the protection unit is outside a given current range ranging from a first threshold current to a second threshold current.

18. The on-board power supply system of claim 17, wherein the first threshold current is selected from a current between about −

1A and about −

100μ

A.

19. The on-board power supply system of claim 17, wherein the second threshold current is selected from a current between about 100μ

A and about 1A.

20. The on-board power supply system of claim 17, wherein the current range includes zero.

21. The on-board power supply system of claim 17, wherein the current range is symmetrical relative to zero.

22. The on-board power supply system of claim 17, wherein the current range is asymmetrical relative to zero.

23. The on-board power supply system of claim 1, wherein the protection unit further comprises a diode connected between the first external terminal and the first power supply terminal.

30. The on-board power supply system of claim 1, wherein the control circuit is separate from the semiconductor switching unit and is configured to receive the first voltage and the second voltage.

24. A method for protecting an on-board power supply system that comprises a first power supply terminal and a second power supply terminal configured to have a battery and/or a generator connected thereto, and a first external terminal coupled to the first power supply terminal, and a second external terminal coupled to the second power supply terminal, the method comprising:

connecting a first load between the first and second power supply terminals, wherein connecting the first load comprises applying a first polarity from the first and second power supply terminals to the first load;

connecting a second load between the first and second external terminals;

connecting a protection unit with a semiconductor switching unit between the first external terminal and the first power supply terminal;

switching the semiconductor switching unit on and off dependent on at least one electrical parameter in the on-board power supply system, wherein the at least one electrical parameter comprises a first voltage between the external terminals and a second voltage across the protection unit; and

maintaining the connecting between the first load and the first and second power supply terminals when the semiconductor switching unit is switched off.

25. The method of claim 24, wherein the at least one electrical parameter comprises a current through the protection unit.

26. The method of claim 24, wherein switching comprises switching the semiconductor switching unit on and off dependent on a first voltage between the external terminals and dependent on a second voltage across a load path of the semiconductor switching unit.

27. The method of claim 26, wherein switching comprises switching the semiconductor switching unit on when the first voltage is higher than a first threshold value and when the second voltage is outside a given first voltage range.

28. The method of claim 26, wherein switching comprises switching the semiconductor switching unit on and off dependent on a first voltage between the external terminals and dependent on a current through the protection unit.

29. A control circuit for a power supply protection unit, the control circuit configured to:

receive a first voltage signal corresponding to a voltage difference between a first external terminal and a second external terminal;

receive a second voltage signal corresponding to a voltage difference between the first external terminal and a first power supply terminal;

detect a reverse polarity coupling between the first and second external terminals based on the first voltage signal and the second voltage signal;

provide a control signal to a semiconductor switching unit operable to turn the semiconductor switching unit on or off dependent on the first voltage signal and the second voltage signal based on the detecting; and

electrically disconnect the first external terminal from the first power supply terminal when the semiconductor switching unit is turned off, while an electrical connection between a power supply and a load coupled to the first power supply terminal is maintained.

31. An on-board power supply system, the system comprising:

a first power supply terminal and a second power supply terminal configured to have a battery and/or a generator connected thereto, wherein the power supply system is configured to have a first electrical polarity applied to the first and second power supply terminals;

a first external terminal coupled to the first power supply terminal and a second external terminal coupled to the second power supply terminal; and

a protection unit connected between the first external terminal and the first power supply terminal,

wherein the protection unit comprises;

a semiconductor switching unit having a load path and a control terminal, the load path connected between the first external terminal and the first power supply terminal; and

a control circuit coupled to the control terminal of the semiconductor switching unit and configured to switch the semiconductor switching unit on and off dependent on at least one electrical parameter in the on-board power supply system, wherein

the control circuit is configured to turn the semiconductor switching unit off when the at least one electrical parameter indicates that an electrical polarity applied to the first and second external terminals is opposite the first electrical polarity,

the first electrical polarity is supplied to the first and second power supply terminals and the battery and/or the generator connected thereto when the semiconductor switching unit is turned off, and

the control circuit is separate from the semiconductor switching unit and is configured to receive the at least one electrical parameter.