Method And System For An Adaptive Low-Dropout Regulator

• US 20160085252A1
• Filed: 11/20/2015
• Published: 03/24/2016
• Est. Priority Date: 07/22/2013
• Status: Active Grant

• Current Assignee: Entropic Communications, LLC (SoftBank Group Corp.)
• Original Assignee: Entropic Communications, LLC (SoftBank Group Corp.)
• Inventors: Petrovic, Branislav, Nabicht, Joseph
• Granted Patent: US 10,261,534 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: G05F 1/56 using semiconductor devices in series with the load as final control devices G05F1/461 takes precedence
• CPC Class Codes: G05F 1/575 characterised by the feedback circuit
• CPC Class Codes: G05F 5/00 Systems for regulating electric variables by detecting deviations in the electric input to the system and thereby controlling a device within the system to obtain a regulated output

Abstract

Methods and systems for a low-dropout regulator may comprise a voltage regulator comprising: (a) a pass transistor having a first terminal at a control gate, a voltage input at a second terminal, and a voltage output at a third terminal, and (b) an adaptive control circuit (ACC), electrically coupled to a reference voltage and each of the terminals of the pass transistor. The ACC may determine a AV between the second and third terminals and cause an error signal to be applied to the first terminal to keep AV essentially constant as the voltage input varies. The ACC may include a voltage summing circuit electrically coupled to the reference voltage and the input voltage to generate a comparison value. An error amplifier electrically coupled to the control gate and to the voltage summing circuit may generate the error signal from the comparison value and the output voltage.

Claims

1-12. -12. (canceled)

13. A system for voltage regulation, the system comprising:

a voltage regulator comprising;

(a) a pass transistor having a first terminal at a control gate, a voltage input at a second terminal, and a voltage output at a third terminal; and

(b) an adaptive control circuit, electrically coupled to a reference voltage and the first, second, and third terminals of the pass transistor, the adaptive control circuit determining a difference Δ

V between the second and third terminals of the pass transistor, and causing an error signal to be applied to the first terminal of the pass transistor to keep Δ

V essentially constant as the voltage input varies.

14. The system of claim 13, wherein the adaptive control circuit comprises:

a voltage summing circuit electrically coupled to the reference voltage and the input voltage said voltage summing circuit generating a comparison value, and

an error amplifier, electrically coupled to the control gate of the pass transistor and to the voltage summing circuit, for generating the error signal from the comparison value and the output voltage.

15. The system of claim 13, wherein the adaptive control circuit comprises:

a voltage summing circuit electrically coupled to the reference voltage and the third terminal of the pass transistor, said voltage summing circuit generating a comparison value, and

an error amplifier, electrically coupled to the first terminal of the pass transistor and to the voltage summing circuit, for generating the error signal from the comparison value and the input voltage.

16. The system of claim 13, wherein the voltage regulator is operable to filter the voltage input before determining Δ

V in order to track only moving average changes to the voltage input.

17. The system of claim 13, wherein the pass transistor comprises a metal-oxide semiconductor transistor.

18. The system of claim 13, wherein the reference voltage comprises a bandgap reference.

19. The system of claim 13, wherein the voltage regulator acts as a low-pass filter, regulating input voltages within a loop bandwidth and rejecting input noise and/or ripple voltages above the loop bandwidth.

20. A method of voltage regulation, the method comprising:

in a voltage regulator comprising a pass transistor having a first terminal at a control gate, a voltage input at a second terminal, and a voltage output at a third terminal;

(a) determining a difference Δ

V between the second and third terminals of the pass transistor utilizing an adaptive control circuit coupled to a reference voltage and to the first terminal of the pass transistor; and

(b) controlling the power dissipation of the pass transistor as a function of Δ

V utilizing the adaptive control circuit by applying an error signal to the first terminal of the pass transistor so as to maintain such power dissipation approximately constant as the voltage input varies.

21. The method of claim 20, comprising filtering the voltage input before determining Δ

V in order to track only moving average changes to the voltage input.

22. The method of claim 20, wherein controlling the power dissipation of the pass transistor as a function of Δ

V comprises maintaining Δ

V approximately constant as the voltage input varies.

23. The method of claim 20, wherein the pass transistor comprises a metal-oxide semiconductor transistor.

24. The method of claim 20, wherein the reference voltage comprises a bandgap reference.

25. The method of claim 20, wherein the adaptive control circuit comprises:

a voltage summing circuit electrically coupled to the reference voltage and the second terminal of the pass transistor, said voltage summing circuit generating a comparison value, and

an error amplifier, electrically coupled to the first terminal of the pass transistor and to the voltage summing circuit, for generating the error signal from the comparison value and the output voltage.

26. The method of claim 20, wherein the adaptive control circuit comprises:

a voltage summing circuit electrically coupled to the reference voltage and the output voltage, said voltage summing circuit generating a comparison value, and

an error amplifier, electrically coupled to the first terminal of the pass transistor and to the voltage summing circuit, for generating the error signal from the comparison value and the input voltage.

27. A method of regulating voltage in an adaptive low dropout voltage regulator circuit while maintaining low power dissipation, including:

(a) providing a pass transistor having a first terminal at a control gate, a voltage input at a second terminal, and a voltage output at a third terminal;

(b) providing adaptive control circuitry, electrically coupled to a reference voltage and the first, second, and third terminals of the pass transistor, the adaptive control circuitry for determining a difference Δ

V between the second and third terminals of the pass transistor; and

(c) applying an error signal derived from the adaptive control circuitry to the control gate of the pass transistor to keep Δ

V essentially constant as the voltage input varies.

28. The method of claim 27, comprising filtering the voltage input before determining Δ

V in order to track only moving average changes to the voltage input.

29. The method of claim 27, wherein the reference voltage comprises a bandgap reference.

30. The method of claim 27, wherein the pass transistor comprises a metal-oxide semiconductor transistor.

31. The method of claim 27, wherein the adaptive control circuit comprises:

a voltage summing circuit electrically coupled to the reference voltage and the input voltage, said voltage summing circuit generating a comparison value, and

an error amplifier, electrically coupled to the control gate of the pass transistor and to the voltage summing circuit, for generating the error signal from the comparison value and the output voltage

32. The method of claim 27, wherein the adaptive control circuit comprises:

a voltage summing circuit electrically coupled to the reference voltage and the output voltage, said voltage summing circuit generating a comparison value, and

an error amplifier, electrically coupled to the control gate of the pass transistor and to the voltage summing circuit, for generating the error signal from the comparison value and the input voltage.