Voltage droop control in a voltage-regulated switched mode power supply

Patent metadata

Field	Value
Publication number	US-9401640-B2
Application number	US-201314347322-A
Country	US
Kind code	B2
Filing date	Apr 11, 2013
Priority date	Apr 11, 2013
Publication date	Jul 26, 2016
Grant date	Jul 26, 2016

Abstract

A switched mode power supply (SMPS) comprising a controller configured to control switching of the SMPS to regulate an output voltage at an output of the SMPS based on a feedback signal that indicates the output voltage, and a voltage droop control circuit. The voltage droop control circuit comprises a voltage droop control signal generator that detects a voltage drop across a component of the SMPS that is indicative of a current flowing through the output of the SMPS during operation. The voltage droop control signal generator is an active device arranged to generate, based on the detected voltage drop, an output voltage droop control signal for causing the controller to adjust the regulation of the output voltage. The voltage droop control circuit further comprises a reference voltage generator arranged to bias at least one of the first and second inputs of the voltage droop control signal generator.

First claim

The invention claimed is:

1. A switched mode power supply comprising:
a controller configured to control switching of the switched mode power supply to regulate an output voltage at an output of the switched mode power supply based on a feedback signal that is indicative of the output voltage; and
a voltage droop control circuit comprising:
a voltage droop control signal generator having a first input and a second input coupled so as to detect a voltage drop across a component of the switched mode power supply that is indicative of a current flow through the output of the switched mode power supply during operation, and in which the second input is coupled to the output,

wherein the voltage droop control signal generator is an active device that is arranged to generate, based on the detected voltage drop, an output voltage droop control signal that causes the controller, along with the feedback signal, to adjust the regulation of the output voltage; and
a reference voltage generator arranged to provide a voltage reference to bias the second input of the voltage droop control signal generator to adjust the regulation of the output voltage when the current flow is out of the output and also to adjust the regulation of the output voltage when the current flow is into the output.

2. The switched mode power supply according to claim 1 , wherein the voltage droop control signal generator is arranged to detect, via the first and second inputs, a voltage difference across a capacitor that is indicative of at least a portion of a voltage drop across an inductor that is connected serially to the current flow at the output of the switched mode power supply, and to generate the output voltage droop control signal based on the detected voltage difference, such that the output voltage droop control signal is indicative of the current flow through the inductor.

3. The switched mode power supply according to claim 1 , wherein the voltage droop control signal generator is arranged to generate the output voltage droop control signal whose amplitude is limited by a voltage of a voltage source used to power the voltage droop control signal generator.

4. The switched mode power supply according to claim 3 , wherein the voltage droop control signal generator is an operational amplifier.

5. The switched mode power supply according to claim 1 , wherein the reference voltage generator is arranged to bias the second input of the voltage droop control signal generator via a buffer.

6. The switched mode power supply according to claim 1 , wherein the controller comprises an operational amplifier arranged to receive the feedback signal and the output voltage droop control signal at different inputs of the operational amplifier and to control switching of the switched mode power supply based on the received signals.

7. A power supply system comprising a plurality of switched mode power supplies that are coupled in parallel to supply power to a load, wherein at least one of the plurality of switched mode power supplies comprises a particular type of switched mode power supply that comprises:
a controller configured to control switching of the particular type of switched mode power supply to regulate an output voltage at an output of the particular type of switched mode power supply based on a feedback signal that is indicative of the output voltage; and
a voltage droop control circuit comprising:
a voltage droop control signal generator having a first input and a second input coupled so as to detect a voltage drop across a component of the particular type of switched mode power supply that is indicative of a current flow through the output of the particular type of switched mode power supply during operation, and in which the second input is coupled to the output,

wherein the voltage droop control signal generator is an active device that is arranged to generate, based on the detected voltage drop, an output voltage droop control signal that causes the controller, along with the feedback signal, to adjust the regulation of the output voltage; and
a reference voltage generator arranged to provide a voltage reference to bias the second input of the voltage droop control signal generator to adjust the regulation of the output voltage when the current flow is out of the output and also to adjust the regulation of the output voltage when the current flow is into the output.

8. The power supply system according to claim 7 , wherein each of the plurality of switched mode power supplies comprises the particular type of switched mode power supply.

9. The switched mode power supply according to claim 7 , wherein the voltage droop control signal generator is arranged to detect, via the first and second inputs, a voltage difference across a capacitor that is indicative of at least a portion of a voltage drop across an inductor that is connected serially to the current flow at the output of the switched mode power supply, and to generate the output voltage droop control signal based on the detected voltage difference, such that the output voltage droop control signal is indicative of the current flow through the inductor.

10. The switched mode power supply according to claim 7 , wherein the voltage droop control signal generator is arranged to generate the output voltage droop control signal whose amplitude is limited by a voltage of a voltage source used to power the voltage droop control signal generator.

11. The switched mode power supply according to claim 10 , wherein the voltage droop control signal generator is an operational amplifier.

12. The switched mode power supply according to claim 7 , wherein the reference voltage generator is arranged to bias the second input of the voltage droop control signal generator via a buffer.

13. The switched mode power supply according to claim 7 , wherein the controller comprises an operational amplifier arranged to receive the feedback signal and the output voltage droop control signal at different inputs of the operational amplifier and to control switching of the switched mode power supply based on the received signals.

Assignees

• Ericsson Telefon Ab L M

Inventors

• Karlsson Magnus
• Persson Oscar
• Svensson Andreas

Classifications

• H02M3/285

  Single converters with a plurality of output stages connected in parallel (parallel operation of a plurality of converters in DC distribution networks H02J1/10) · CPC title

• H02M3/156

  with automatic control of output voltage or current, e.g. switching regulators · CPC title

• H02M3/1584

  with a plurality of power processing stages connected in parallel · CPC title

• H02M2001/0025

  Electricity · mapped topic

• H02M2007/4822

  Electricity · mapped topic