Multimode voltage regulator and method for providing a multimode voltage regulator output voltage and an output current to a load

• US 8,618,780 B2
• Filed: 11/24/2008
• Issued: 12/31/2013
• Est. Priority Date: 11/24/2008
• Status: Active Grant

• Current Assignee: NXP USA, Inc. (NXP Semiconductors NV)
• Original Assignee: Freescale Semiconductor, Inc. (NXP Semiconductors NV)
• Inventors: Mounier, Philippe, Huynh, Estelle, Lopez, David, Sicard, Thierry
• Primary Examiner(s): Vu, Bao Q
• Assistant Examiner(s): TSEHAYE, ZEKRE A
• Application Number:
  US13/125,856
• Publication Number:
  US 20110210709A1
• Time in Patent Office: 1,863 Days
• Field of Search: 323273-271, 323273-281, 713320-323
• US Class Current: 323/277
• CPC Class Codes: H02J 1/14 Balancing the load in a network
• CPC Class Codes: H02J 2310/40 The network being an on-board power network, i.e. within a vehicle
• CPC Class Codes: H02J 2310/44 for aircrafts
• CPC Class Codes: H02J 9/005 using a power saving mode for copiers G03G15/5004

Abstract

A multimode voltage regulator comprises an output for providing a regulator output voltage Vdd and an output current to a load and a low power reference voltage source having a reference voltage output providing the regulator output voltage Vdd, when in a first low power mode the output current is not greater than a threshold value. It may comprise a buffer amplifier having an output providing the regulator output voltage Vdd, when the output current is greater than the threshold value and a first bias voltage input being connected in a second low power mode to the reference voltage output when the output current is greater than the threshold value for less than a predefined time. And it may comprise a mode controller for automatically determining the output current and automatically switching from first low power mode to second low power mode.

Claims

1. A multimode voltage regulator, comprising

an output for providing a regulator output voltage and an output current to a load;

a low power reference voltage source having;

a reference voltage output providing said regulator output voltage, when in a first low power mode an absolute value of said output current is not greater than a threshold value;

a buffer amplifier having a buffer amplifier output providing said regulator output voltage, when said absolute value of said output current is greater than said threshold value;

a first bias voltage input being connected in a second low power mode to said reference voltage output when said absolute value of said output current is greater than said threshold value for less than a predefine time; and

a second bias voltage input being connected in a third normal mode to a bias voltage output of a bias voltage source when said absolute value of said output current is greater than said threshold value for at least said predefined time; and

a mode controller for automatically determining said absolute value of said output current and automatically switching from said first low power mode to said second low power mode.

2. The multimode voltage regulator as claimed in claim 1, wherein said automatic switching between said first low power mode and said second low power mode is triggered by a cyclic change of said absolute value of said output current.

3. The multimode voltage regulator as claimed in claim 1, wherein said predefined time is provided by a programmable timer.

4. The multimode voltage regulator as claimed in claim 1, wherein a controller unit connected to said regulator output is operable at a maximum current capability without said regulator receiving a prior wake-up signal.

5. The multimode voltage regulator as claimed in claim 1, comprising switches for automatically switching from said second low power mode to said first low power mode after a transition of said absolute value of said output current from a value greater than said threshold value to a value below said threshold value.

6. The multimode voltage regulator as claimed in claim 1, wherein in a fourth mode neither said buffer amplifier nor said reference voltage source provide said regulator output voltage.

7. The multimode voltage regulator as claimed in claim 1, wherein said buffer amplifier is a voltage follower circuit.

8. The multimode voltage regulator as claimed in claim 1, wherein a current consumption when cyclically switching between said first low power mode and said second low power mode is less than eighty percent of said consumption when cyclically switching directly between said first low power mode and said third normal mode.

10. A system base chip, comprising

a multimode voltage regulator as claimed in claim 1.

12. A computer program product, comprising code portions for executing steps of a method as claimed in claim 8.

9. A method for providing a multimode voltage regulator output voltage and an output current to a load, the method comprising

providing said regulator output voltage by a reference voltage output of a low power reference voltage source when in a first low power mode an absolute value of said output current is not greater than a threshold value;

providing said regulator output voltage by a buffer amplifier output of a buffer amplifier having a first bias voltage input being connected in a second low power mode to said reference voltage output when said absolute value of said output current is greater than said threshold value for less than a predefined time;

automatically determining said absolute value of said output current;

automatically switching from said first low power mode to said second low power mode; and

providing said regulator output voltage by said buffer amplifier output of said buffer amplifier having a second bias voltage input being connected in a third normal mode to a bias voltage output of a bias voltage source when said absolute value of said output current is greater than said threshold value for at least said predefined time.

11. A vehicle comprising a system base chip as claimed in claim 9.

13. The method of claim 9, wherein automatically switching between the first low power mode and the second low power mode is triggered by a cyclic change of the absolute value of the output current.

14. The method of claim 9, wherein a current consumption when cyclically switching between the first low power mode and the second low power mode is less than eighty percent of the consumption when cyclically switching directly between the first low power mode and the third normal mode.

15. A method comprising:

providing only an internal voltage of a low power reference voltage source when the low power reference voltage source is in an ultra low power mode;

providing, by a reference voltage output of the low power reference voltage source, a regulator output voltage when the low power reference voltage source is in a first low power mode, and in response to an absolute value of an output current being less than a threshold value;

providing, by a buffer amplifier output of a buffer amplifier having a first bias voltage input being connected to the reference voltage output when the low power reference voltage source is in a second low power mode, the regulator output voltage in response to the absolute value of the output current being greater than the threshold value for less than a predefined time;

automatically determining the absolute value of said output current;

automatically switching from the first low power mode to said second low power mode; and

providing, by the buffer amplifier output of the buffer amplifier having a second bias voltage input being connected to a bias voltage output of a bias voltage source in a normal mode, the regulator output voltage in response to the absolute value of the output current being greater than the threshold value for at least said predefined time.

16. The multimode voltage regulator of claim 15, wherein the automatic switching between the first low power mode and the second low power mode is triggered by a cyclic change of the absolute value of the output current.

17. The multimode voltage regulator of claim 15, wherein a controller unit connected to the regulator output is operable at a maximum current capability without the regulator receiving a prior wake-up signal.

18. The method of claim 15, further comprising:

automatically switching from the second low power mode to the first low power mode after a transition of the absolute value of the output current from a value greater than the threshold value to a value below the threshold value.

19. The method of claim 15, wherein the predefined time is provided by a programmable timer.

20. The multimode voltage regulator of claim 15, wherein a current consumption when cyclically switching between the first low power mode and the second low power mode is less than eighty percent of the consumption when cyclically switching directly between the first low power mode and the third normal mode.