Method and apparatus for providing a regulated voltage at a voltage output

• US 7,626,368 B2
• Filed: 04/11/2007
• Issued: 12/01/2009
• Est. Priority Date: 04/11/2006
• Status: Active Grant

• Current Assignee: Infineon Technologies AG
• Original Assignee: Infineon Technologies AG
• Inventors: Novak, Heinz
• Primary Examiner(s): HAN, YOUNGHUIE JESSICA
• Application Number:
  US11/734,029
• Publication Number:
  US 20070236279A1
• Time in Patent Office: 965 Days
• Field of Search: 323312-315, 323/274, 323/275, 323/280, 323/285, 307/43, 307/75, 327/540
• US Class Current: 323/275
• CPC Class Codes: G05F 1/565 sensing a condition of the system or its load in addition to means responsive to deviations in the output of the system, e.g. current, voltage, power factor G05F1/563 takes precedence

Abstract

An apparatus for supplying a glitch-free, regulated voltage at a voltage output includes a main transistor, which is connected between an intermediate potential and the voltage output, a bypass transistor, which is connected between a supply potential and the voltage output, the intermediate potential being lower than the supply potential and the intermediate potential and the supply potential being derived from a common voltage source, a regulation circuit for applying a main control potential to the main transistor, in order to regulate a voltage at the voltage output to a desired voltage, and a control circuit for generating a bypass control potential as a function of the supply potential and the main control potential, and to apply the bypass control potential to the bypass transistor.

Claims

1. An apparatus for providing a regulated voltage at a voltage output, comprising:

a main transistor, which is connected between an intermediate potential and the voltage output;

a bypass transistor, which is connected between a supply potential and the voltage output, the intermediate potential being lower than the supply potential and the intermediate potential and the supply potential being derived from a common voltage source;

a regulation circuit for applying a main control potential to the main transistor, in order to regulate a voltage at the voltage output to a desired voltage; and

a control circuit for generating a bypass control potential as a function of the supply potential and the main control potential, and for applying the bypass control potential to the bypass transistor.

2. The apparatus according to claim 1, wherein the control circuit comprises an impedance element, which comprises a first terminal and a second terminal, the first terminal being connected to a control terminal of the main transistor at which is present the main control potential, and the second terminal being connected to a control terminal of the bypass transistor.

3. The apparatus according to claim 2, wherein the impedance element is a resistive element.

4. The apparatus according to claim 2, wherein the control circuit comprises a current-supply controlled as a function of the supply potential, which is formed so as to supply through the impedance element a current flow depending on the supply potential.

5. The apparatus according to claim 2, wherein the control circuit comprises a current-supply controlled as a function of the supply potential, which is connected between the second terminal of the impedance element and a reference potential, in order to create through the impedance element a current flow as a function of the supply potential.

6. The apparatus according to claim 2, wherein the impedance element is a resistive element with an adjustable resistance value, and the control circuit comprises a current-supply for supplying a constant current flow through the resistive element with adjustable resistance value and is formed so as to change the resistance value of the resistive element as a function of the supply potential.

7. The apparatus according to claim 1, wherein the control circuit is formed such that the generation of the bypass control potential occurs in a way continuously changing as a function of the supply potential.

8. The apparatus according to claim 1, wherein the control circuit comprises a current-supply controlled as a function of the supply potential, which comprises a first current mirror and a second current mirror for mirroring a launched current, which are connected so that a sink terminal of a first transistor of the first current mirror is connected to the source terminal of a second transistor the sink and control terminals of which are connected, and which is connected to the source terminal of a third transistor the control terminal of which is coupled to the voltage output and the sink terminal of which is connected to the sink and control terminals of a fourth transistor belonging to the second current mirror.

9. A method for providing a regulated voltage at a voltage output by means of a main transistor, which is connected between an intermediate potential and the voltage output, and a bypass transistor, which is connected between a supply potential and the voltage output, the intermediate potential being lower than the supply potential and the intermediate potential and the supply potential being derived from a common voltage source, the method comprising:

applying a main control potential to the main transistor, in order to regulate a voltage at the voltage output to a desired voltage;

generating a bypass control potential as a function of the supply potential and the main control potential; and

applying the bypass control potential to the bypass transistor.

10. A computer program with a program code for performing, when the computer program is executed on a computer and/or a microcontroller, a method for providing a regulated voltage at a voltage output by means of a main transistor, which is connected between an intermediate potential and the voltage output, and a bypass transistor, which is connected between a supply potential and the voltage output, the intermediate potential being lower than the supply potential and the intermediate potential and the supply potential being derived from a common voltage source, the method comprising:

applying a main control potential to the main transistor, in order to regulate a voltage at the voltage output to a desired voltage;

generating a bypass control potential as a function of the supply potential and the main control potential; and

applying the bypass control potential to the bypass transistor.

11. An apparatus for providing a regulated voltage at a voltage output, comprising:

a first transistor connected between a first potential and the voltage output;

a second transistor connected between a second potential and the voltage output, wherein the first potential is lower than the second potential;

a regulation circuit generating a control signal fed to the first transistor, in order to regulate the voltage output; and

a control circuit controlling the second transistor as a function of the second potential and the control signal.

12. The apparatus according to claim 11, wherein the first and second potential are derived from a common voltage source.

13. The apparatus according to claim 11, wherein the control circuit comprises an impedance element, which comprises a first terminal and a second terminal, the first terminal being connected to a control terminal of the first transistor, and the second terminal being connected to a control terminal of the second transistor.

14. The apparatus according to claim 13, wherein the impedance element is a resistive element.

15. The apparatus according to claim 13, wherein the control circuit generates a current as a function of the second potential.

16. The apparatus according to claim 13, wherein the control circuit comprises a current-supply controlled as a function of the second potential, which is connected between the second terminal of the impedance element and a reference potential, in order to create through the impedance element a current flow as a function of the supply potential.

17. The apparatus according to claim 13, wherein the impedance element is a resistive element with an adjustable resistance value, and the control circuit comprises a current-supply for supplying a constant current flow through the resistive element with adjustable resistance value and is formed so as to change the resistance value of the resistive element as a function of the second potential.

18. The apparatus according to claim 11, wherein the control circuit is formed such that the generation of a control potential at the second transistor occurs in a way continuously changing as a function of the second potential.

19. The apparatus according to claim 11, wherein the control circuit comprises a current-supply controlled as a function of the second potential, which comprises a first current mirror and a second current mirror for mirroring a current, which are connected so that a sink terminal of a third transistor of the first current mirror is connected to the source terminal of a fourth transistor, the sink and control terminals of which are connected, and which is connected to the source terminal of a fifth transistor, the control terminal of which is coupled to the voltage output and the sink terminal of which is connected to the sink and control terminals of a sixth transistor belonging to the second current mirror.