Charge sharing linear voltage regulator

Patent metadata

Field	Value
Publication number	US-9645591-B2
Application number	US-201414151701-A
Country	US
Kind code	B2
Filing date	Jan 9, 2014
Priority date	Jan 9, 2014
Publication date	May 9, 2017
Grant date	May 9, 2017

Abstract

Exemplary embodiments are related to voltage regulators. A device may include a first energy storage element coupled between a ground voltage and an output. The device may also include a second energy storage element coupled to the ground voltage and configured to selectively couple to the output. Further, the device may include a voltage regulator coupled between an input and the second energy storage element.

First claim

What is claimed is:

1. A device, comprising:
a first energy storage element coupled to an output;
a second energy storage element configured to selectively and periodically couple to the first energy storage element and the output based on an active load period of a load coupled to the output;
a voltage regulator coupled between an input and the second energy storage element, the voltage regulator is configured to receive a feedback voltage, which is a voltage of the first energy storage element, and charge the second energy storage to a voltage based on the feedback voltage; and
a second voltage regulator coupled between the input and the first energy storage element configured to charge the first energy storage element.

2. The device of claim 1 , wherein each of the first energy storage element and the second energy storage element comprises a capacitor.

3. The device of claim 1 , further comprising a switch configured to selectively couple the second energy storage element to the output.

4. The device of claim 1 , wherein the voltage regulator is further configured to convey an output voltage based on a voltage ripple at the output.

5. A method, comprising:
charging a first energy storage element coupled to an output of a voltage regulator to a first voltage;
charging a second energy storage element coupled to an output of a second voltage regulator to a second voltage;
coupling periodically the first energy storage element to the second energy storage element during an active load period to compensate for a load current at the second energy storage element; and
conveying a feedback voltage from the second energy storage element to the voltage regulator, wherein the feedback voltage is the second voltage of the second energy storage element, and the first voltage is based on the feedback voltage.

6. A device, comprising:
a voltage regulator configured to receive an input voltage and convey an output voltage to a first node;
a first energy storage element coupled to the first node;
a second energy storage element coupled to an output node;
a switch configured to periodically couple the first energy storage element to the output node during an active load period at the output node, wherein the voltage regulator is configured to receive a feedback voltage from the output node, the feedback voltage is a voltage of the second energy storage element, and the output voltage is based on the feedback voltage; and
a second voltage regulator configured to receive the input voltage and convey an output voltage to the output node.

7. The device of claim 6 , wherein a voltage at the output node is less than a voltage at the first node.

8. The device of claim 6 , wherein the second energy storage element is configure to be charged to a target DC voltage.

9. The device of claim 6 , wherein the output node is configured to couple to a target block.

10. The method of claim 5 , further comprising receiving an input voltage at the voltage regulator and the second voltage regulator.

11. The method of claim 5 , wherein charging the second energy storage element to a second voltage comprises charging the second energy storage element to the second voltage less than the first voltage.

12. A method, comprising:
conveying a first output voltage from a first voltage regulator to a first capacitor coupled to an output;
conveying a second output voltage from a second voltage regulator to a second capacitor;
selectively and periodically coupling the second capacitor to the output during an active load period to compensate for a load current at the output; and
conveying a feedback voltage from the output to the second voltage regulator, wherein the feedback voltage is a voltage of the first capacitor, and the second output voltage is based on the feedback voltage.

13. The method of claim 12 , wherein conveying a first output voltage comprises charging the first capacitor to a target DC voltage.

14. The method of claim 12 , wherein conveying a second output voltage comprises charging the second capacitor based on a voltage ripple at the output.

15. The method of claim 12 , further comprising receiving an input voltage at each of the first voltage regulator and the second voltage regulator.

16. A device, comprising:
means for charging a first energy storage element coupled to an output of a voltage regulator to a first voltage;
means for charging a second energy storage element coupled to an output of a second voltage regulator to a second voltage; and
means for coupling periodically the first energy storage element to the second energy storage element during an active load period to compensate for a load current at the output, wherein the means for charging the second energy storage element receives a feedback voltage from the output, the feedback voltage is the second voltage of the second energy storage element, and the second voltage is based on the feedback voltage.

17. A device, comprising:
means for conveying a first output voltage from a first voltage regulator to a first capacitor coupled to an output;
means for conveying a second output voltage from a second voltage regulator to a second capacitor; and
means for selectively and periodically coupling the second capacitor to the output during an active load period to compensate for a load current at the output, wherein the second voltage regulator receives a feedback voltage from the output, the feedback voltage is a voltage of the first capacitor, and the second output voltage is based on the feedback voltage.

Assignees

• Qualcomm Inc

Inventors

• Roham Masoud
• Zheng Wei
• Dai Liang
• Alladi Dinesh J
• Guo Yuhua

Classifications

• G05F1/56 Primary

  using semiconductor devices in series with the load as final control devices (G05F1/461 takes precedence) · CPC title

• G05F1/575 Primary

  characterised by the feedback circuit · CPC title