Self-adjusting regulator and method of using same

Patent metadata

Field	Value
Publication number	US-9312759-B2
Application number	US-201314030573-A
Country	US
Kind code	B2
Filing date	Sep 18, 2013
Priority date	Sep 18, 2013
Publication date	Apr 12, 2016
Grant date	Apr 12, 2016

Abstract

A self-adjusting regulator includes a power stage adjusting an output voltage and a control loop for controlling the power stage. The control loop includes a compensator adjusting a bandwidth in response to at least one compensator control signal, and an oscillator controlling a switching speed in response to at least one oscillator control signal. The self-adjusting regulator further includes a voltage sensing control circuit controlling the control loop. The voltage sensing control circuit generating the at least one compensator control signal and the at least one oscillator control signal based on a comparison of the output voltage and a reference voltage. In a low speed mode, the compensator outputs a first bandwidth, and the oscillator outputs a first switching speed. In a high speed mode, the compensator outputs a second bandwidth greater than the first bandwidth, and the oscillator outputs a second switching speed faster than the first switching speed.

First claim

What is claimed is:

1. A self-adjusting regulator comprising:
a power stage configured to adjust an output voltage;
a control loop configured to control the power stage, the control loop comprising:
a compensator configured to adjust a bandwidth of the self-adjusting regulator in response to at least one compensator control signal, and
an oscillator configured to output an oscillation signal for controlling a switching speed of the self-adjusting regulator in response to at least one oscillator control signal; and

a voltage sensing control circuit configured to control the control loop, the voltage sensing control circuit configured to receive the output voltage and a reference voltage and to generate the at least one compensator control signal and the at least one oscillator control signal based on a comparison of the output voltage and the reference voltage,
wherein in a low speed mode the compensator is configured to output a first bandwidth, and the oscillator is configured to output a first switching speed, and
in a high speed mode the compensator is configured to output a second bandwidth greater than the first bandwidth, and the oscillator is configured to output a second switching speed faster than the first switching speed.

2. The self-adjusting regulator of claim 1 , wherein the compensator comprises:
at least one variable capacitor, wherein each variable capacitor of the at least one variable capacitor is configured to receive a corresponding compensator control signal of the at least one compensator control signal; and
at least one variable resistor, wherein each variable resistor of the at least one variable resistor is configured to receive a corresponding compensator control signal of the at least one compensator control signal.

3. The self-adjusting regulator of claim 2 , wherein the at least one variable capacitor comprises a first variable capacitor and a second variable capacitor connected in parallel, and the at least one variable resistor comprises a first variable resistor connected in series with the second variable capacitor.

4. The self-adjusting regulator of claim 2 , wherein the at least one variable capacitor comprises:
a decoder circuit configured to receive the corresponding compensator control signal of the at least one compensator control signal, and to output a decoder signal;
N switches, each switch of the N switches configured to receive the decoder signal; and
N capacitors, each capacitor of the N capacitors connected to a corresponding switch of the N switches, wherein the N capacitors are configured to be connected in parallel.

5. The self-adjusting regulator of claim 2 , wherein the at least one resistor comprises:
a decoder circuit configured to receive the corresponding compensator control signal of the at least one compensator control signal, and to output a decoder signal;
M switches, each switch of the M switches configured to receive the decoder signal; and
M resistor, each resistor of the M resistor connected to a corresponding switch of the M switches, wherein the M resistors are configured to be connected in parallel.

6. The self-adjusting regulator of claim 1 , wherein the control loop further comprises a bias circuit configured to receive the at least on oscillation control signal and adjust a bias current in response to the at least one oscillation control signal, wherein the oscillator is configured to receive the bias current.

7. The self-adjusting regulator of claim 1 , wherein the control loop further comprising a comparator configured to receive an output of the compensator and an output of the oscillator, the comparator configured to output a comparator signal receivable by the power stage.

8. The self-adjusting regulator of claim 7 , wherein the control loop further comprises:
a soft start module configured to control a voltage supplied to the power stage during a startup operation, to generate a startup voltage, and to generate a selector signal; and
a multiplexer configured to receive the comparator signal as a first input, the startup voltage as a second input, and the selector signal as a selector input, wherein the multiplexer is electrically connected between the comparator and the power stage.

9. The self-adjusting regulator of claim 1 , wherein the power stage comprises:
a driver configured to receive a signal from the control loop and to output a driver signal; and
a power stage circuit configured to receive the driver signal and adjust the output voltage.

10. The self-adjusting regulator of claim 9 , wherein the voltage sensing control circuit comprises:
a first transistor having a gate configured to receive the driver signal and a first terminal connected to an operating voltage source; and
a second transistor having a gate configured to receive the driver signal and a first terminal connected to a reference voltage, wherein a second terminal of the first transistor is connected to a second terminal of the second transistor.

11. The self-adjusting regulator of claim 1 , wherein the voltage sensing control circuit comprises a voltage sensing circuit, and the voltage sensing circuit comprises:
a first comparator configured to receive the output voltage and the reference voltage and to output a first voltage difference signal;
a second comparator configured to receive the output voltage and the reference voltage and to output a second voltage difference signal;
a first counter configured to receive a reset signal, the oscillation signal and the first voltage difference signal and to output a first enable signal;
a second counter configured to receive the reset signal, the oscillation signal and the second voltage difference signal, and to output a second enable signal; and
an OR gate configured to receive the first enable signal and the second enable signal, and to output a speed mode signal for generating the at least one oscillator control signal and the at least one compensator control signal.

12. The self-adjusting regulator of claim 1 , wherein the oscillator comprises a sawtooth oscillator.

13. The self-adjusting regulator of claim 1 , wherein in the first switching speed ranges from about 5 Megahertz (MHz) to about 10 MHz.

14. The self-adjusting regulator of claim 1 , wherein a power efficiency of the self-adjusting regulator in the low speed mode is about 90%, and a power efficiency of the self-adjusting regulator in the high speed mode is about 80%.

15. The self-adjusting regulator of claim 1 , wherein the second switching speed ranges from about 100 MHz to about 500 MHz.

16. A method of using a self-adjusting regulator, the method comprises:
generating an output voltage;
receiving a reference voltage;
determining a difference between the reference voltage and the output voltage;
generating at least one oscillation control signal to adjust a switching rate of the self-adjusting regulator based on the difference between the reference voltage and the output voltage; and
generating at least one bandwidth control signal to adjust a bandwidth of the self-adjusting regulator based on the difference between the reference voltage and the output voltage.

17. The method of claim 16 , wherein generating the at least one oscillation control signal comprises:
generating at least one first oscillation control signal corresponding to a first switching rate of the self-adjusting regulator if the difference between the reference voltage and the output voltage exceeds a threshold value; and
generating at least one second oscillation control signal corresponding to a second swi

Assignees

• Taiwan Semiconductor Mfg

Inventors

• Hsu Ying-Chih
• Roth Alan
• Soenen Eric

Classifications

• H02M3/156 Primary

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

• H02M3/1588

  comprising at least one synchronous rectifier element (H02M3/1582, H02M3/1584 take precedence) · CPC title

• H02M3/157

  with digital control · CPC title

• H02M2001/0025

  Electricity · mapped topic

• H02M2003/1566

  Electricity · mapped topic