Shunt regulator

• US 20070200536A1
• Filed: 02/16/2007
• Published: 08/30/2007
• Est. Priority Date: 02/17/2006
• Status: Active Grant

• Current Assignee: Infineon Technologies AG
• Original Assignee: Infineon Technologies AG
• Inventors: Dias, Victor, Riccio, Roberta
• Granted Patent: US 8,085,006 B2
• Time in Patent Office: Days
• US Class Current: 323/224
• CPC Class Codes: G05F 1/613 using semiconductor devices in parallel with the load as final control devices G05F1/461 takes precedence

Abstract

A shunt regulator for stepping down an input potential to an output potential, has an input for applying the input potential, an output for tapping off the output potential and a voltage drop circuit, across which the voltage difference between the input potential and the output potential drops. It is possible for the current flowing through the voltage drop circuit or its lower and/or upper limit value to be adjusted.

Claims

1. A shunt regulator for stepping down an input potential to an output potential, the shunt regulator comprising:

an input terminal for applying the input potential;

an output terminal for tapping off the output potential; and

a voltage drop circuit coupled between the input terminal and the output terminal and across which, during operation of the shunt regulator, the voltage difference between the input potential and the output potential drops, a current flowing through the voltage drop circuit or its limit value being adjustable.

2. The shunt regulator according to claim 1, further comprising:

a control unit for causing the current flowing through the voltage drop circuit or its limit value to be adjusted, the adjustments taking place as a function of the input potential and/or at least one predetermined value for the limit value.

3. The shunt regulator according to claim 1, wherein the voltage drop circuit comprises at least one nonreactive resistor, coupled into its current path and having an adjustable resistance value.

4. The shunt regulator according to claim 1, wherein the voltage drop circuit has at least one resistor, which can be bridged and is coupled into its current path.

5. The shunt regulator according to claim 2, wherein the voltage drop circuit comprises at least one transistor, coupled with its load path into the current path of the voltage drop circuit and which is driven, via a control terminal, by the control unit.

6. The shunt regulator according to claim 5, wherein the voltage drop circuit further comprises at least one nonreactive resistor, coupled into the current path of the voltage drop circuit.

7. The shunt regulator according to claim 6, wherein the at least one transistor is at least one field effect transistor.

8. The shunt regulator of claim 7 wherein the field effect transistor is optionally operated in the triode region or in the saturation region.

9. The shunt regulator according to claim 6, wherein the control unit is designed such that it compares the input potential or a potential, derived from the input potential with a threshold value and, as a function of the threshold value comparison, drives the at least one transistor.

10. The shunt regulator according to claim 7, further comprising a voltage divider that divides the input potential into at least one subpotential, wherein the control unit adjusts the current flowing through the voltage drop circuit or its limit value as a function of the at least one subpotential.

11. The shunt regulator according to claim 10, wherein the control unit is designed such that it compares the at least one subpotential with a threshold value and, as a function of the threshold value comparison, drives the at least one transistor.

12. The shunt regulator according to claim 10, wherein the control unit is designed such that it increases the gate potential of the at least one field effect transistor as the input potential increases if the at least one field effect transistor is operated in the saturation region.

13. The shunt regulator according to claim 1, wherein the input potential and the output potential relate to a common fixed reference potential.

14. The shunt regulator according to claim 13, wherein the input potential and the output potential relate to a ground potential.

15. The shunt regulator according to one claim 1, wherein the shunt regulator is integrated monolithically on a substrate.

16. The shunt regulator according to claim 1, further comprising:

a controllable component, whose load path is coupled between the output terminal and a common fixed potential; and

a control element, which drives the controllable component such that a predetermined output potential is applied to the output terminal.

17. The shunt regulator according to claim 16, wherein the control element is designed such that it compares the output potential or a potential derived therefrom with a reference potential and, as a function of the comparison, drives the controllable component.

18. The shunt regulator according to claim 16, wherein the controllable component comprises a field effect transistor and where the control element comprises an operational amplifier with an output coupled to a gate of the field effect transistor.

19. The shunt regulator according to claim 1, wherein the adjustable limit value of the current flowing through the voltage drop circuit is a lower and/or upper limit value.