System with device startup anticipated voltage supply for voltage output regulation

• US 8,610,417 B1
• Filed: 09/04/2012
• Issued: 12/17/2013
• Est. Priority Date: 01/22/2008
• Status: Active Grant

• Current Assignee: Marvell Asia Pte Limited (Marvell Technology Group Limited)
• Original Assignee: Marvell International Limited (Marvell Technology Group Limited)
• Inventors: Sutardja, Sehat
• Primary Examiner(s): Berhane, Adolf
• Assistant Examiner(s): Jackson, Lakaisha
• Application Number:
  US13/602,760
• Time in Patent Office: 469 Days
• Field of Search: 323/222, 323/268, 323/269, 323/271, 323/272, 323/273, 323/274, 323/275, 323/279, 323/280, 323/281, 323/282, 323/283, 323/284, 323/293, 323/908, 700/297
• US Class Current: 323/282
• CPC Class Codes: G05F 1/563 including two stages of regulation at least one of which is output level responsive, e.g. coarse and fine regulation
• CPC Class Codes: H02M 1/0045 Converters combining the concepts of switch-mode regulation and linear regulation, e.g. linear pre-regulator to switching converter, linear and switching converter in parallel, same converter or same transistor operating either in linear or switching mode

Abstract

A system includes a converter and a regulator. The converter supplies power to a load circuit during an active mode to power first and second devices in the load circuit. The converter is OFF during an inactive mode. The regulator supplies power to the load circuit during the inactive mode to operate the first device in an active state and regulates a power supply voltage, supplied during the inactive mode, to a predetermined voltage. The power supplied during the inactive mode is less than an amount of power to operate the first and second devices in an active state. During the inactive mode, the regulator increases the power supply voltage to a voltage greater than the predetermined voltage to prevent the power supply voltage from decreasing to a voltage less than the predetermined voltage due to an increased amount of load as a result of turning ON the second device.

Claims

1. A system comprising:

a converter configured to supply power to a load circuit during an active mode to power a plurality of devices in the load circuit, wherein the plurality of devices comprise a first device and a second device, and wherein the converter is OFF during an inactive mode; and

a regulator configured to (i) supply power to the load circuit during the inactive mode to operate the first device in an active state, and (ii) regulate a power supply voltage of the power, supplied to the load circuit during the inactive mode, to a predetermined voltage, wherein the power supplied to the load circuit during the inactive mode is less than an amount of power to operate (i) the first device in the active state, and (ii) the second device in an active state,

wherein the regulator is configured to, during the inactive mode, increase the power supply voltage to a voltage greater than the predetermined voltage to prevent the power supply voltage from decreasing to a voltage less than the predetermined voltage due to an increased amount of load as a result of turning ON the second device.

2. The system of claim 1, wherein the converter transitions from the inactive mode to the active mode to supply power to turn ON the second device.

3. The system of claim 1, wherein:

the regulator increases the power supply voltage, of the power supplied from the regulator to the load circuit, to a target voltage to supply power to turn ON the second device; and

the target voltage is greater than the predetermined voltage.

4. The system of claim 1, wherein:

the converter converts a first direct current voltage to a second direct current voltage; and

the power supply voltage is equal to second direct current voltage.

5. The system of claim 1, wherein the regulator is OFF during the active mode.

6. The system of claim 1, wherein:

the regulator is configured to remain ON for a predetermined period during a beginning of the active mode to allow the converter to (i) turn ON, and (ii) supply a target voltage to the load circuit;

the target voltage is greater than the predetermined voltage; and

the regulator is configured to turn OFF at an end of the predetermined period.

7. The system of claim 1, further comprising a control module configured to (i) receive a first control signal from the load circuit, (ii) generate a mode signal based on the first control signal, and (iii) generate a second control signal based on the first control signal, wherein:

the first control signal indicates whether to operate in the active mode or the inactive mode;

the converter transitions between an active state and an inactive state in response to the mode signal; and

the regulator transitions between an active state and an inactive state in response to the second control signal.

8. The system of claim 7, wherein, during the inactive mode, the control module is configured to (i) turn ON the regulator for a predetermined period, and (ii) then turn OFF the regulator at an end of the predetermined period.

9. The system of claim 8, wherein:

the converter is configured to, during the predetermined period, transition from the inactive state of the converter to the active state of the converter to power the second device; and

the control module is configured to

during the inactive mode, account for the increased amount of load as a result of initiating the active mode,

based on the increased amount of load as a result of initiating the active mode, set the predetermined period to prevent the power supply voltage from decreasing to a voltage less than the predetermined voltage during the inactive mode,

increase the power supply voltage to the voltage greater than the predetermined voltage at a beginning of the predetermined period, and

during the predetermined period and prior to the active mode, permit the power supply voltage to decrease from the voltage greater than the predetermined voltage.

10. The system of claim 1, further comprising a comparator configured to (i) compare the power supply voltage and a reference voltage, and (ii) generate a control signal based on the comparison between the power supply voltage and the reference voltage,

wherein the regulator increases the power supply voltage to the voltage greater than the predetermined voltage based on the control signal.

11. The system of claim 10, wherein the reference voltage is equal to the predetermined voltage.

12. The system of claim 10, wherein:

during the inactive mode, the regulator is configured to (i) turn ON for a predetermined period, and (ii) then turn OFF at an end of the predetermined period;

the converter is configured to transition from operating in an inactive state to an active state to power the second device during the predetermined period; and

the regulator is configured to, during the predetermined period, increase the power supply voltage to the voltage greater than the predetermined voltage to prevent the power supply voltage from decreasing to the voltage less than the predetermined voltage.

13. The system of claim 12, wherein the converter is configured to be active at an end of the predetermined period.

14. A method comprising:

supplying power from a converter to a load circuit during an active mode to power a plurality of devices in the load circuit, wherein the plurality of devices comprise a first device and a second device, and wherein the converter is OFF during an inactive mode;

supplying power from a regulator to the load circuit during the inactive mode to operate the first device in an active state;

regulating a power supply voltage of the power, supplied to the load circuit during the inactive mode, to a predetermined voltage, wherein the power supplied to the load circuit during the inactive mode is less than an amount of power to operate (i) the first device in the active state, and (ii) the second device in an active state; and

during the inactive mode, increasing the power supply voltage to a voltage greater than the predetermined voltage to prevent the power supply voltage from decreasing to a voltage less than the predetermined voltage due to an increased amount of load as a result of turning ON the second device.

15. The method of claim 14, further comprising transitioning the converter from an inactive state to an active state to supply power to turn ON the second device.

16. The method of claim 14, further comprising increasing the power supply voltage, of the power supplied from the regulator to the load circuit, a target voltage to supply power to turn ON the second device, wherein the target voltage is greater than the predetermined voltage.

17. The method of claim 14, further comprising

receiving a first control signal from the load circuit;

generating a mode signal based on the first control signal;

generating a second control signal based on the first control signal,

wherein the first control signal indicates whether to operate in the active mode or the inactive mode;

transitioning the converter between an active state and an inactive state in response to the mode signal; and

transitioning the regulator between an active state and an inactive state in response to the second control signal.

18. The method of claim 17, further comprising, during the inactive mode:

turning ON the regulator for a predetermined period; and

then turning OFF the regulator at an end of the predetermined period.

19. The method of claim 18, further comprising

during the predetermined period, transitioning the converter from the inactive state of the converter to the active state of the converter to power the second device;

during the inactive mode, accounting for the increased amount of load as a result of initiating the active mode;

based on the increased amount of load as a result of initiating the active mode, setting the predetermined period to prevent the power supply voltage from decreasing to a voltage less than the predetermined voltage during the inactive mode;

increasing the power supply voltage to the voltage greater than the predetermined voltage at a beginning of the predetermined period; and

during the predetermined period and prior to the active mode, permitting the power supply voltage to decrease from the voltage greater than the predetermined voltage.

20. The method of claim 14, further comprising

comparing the power supply voltage and a reference voltage;

generating a control signal based on the comparison between the power supply voltage and the reference voltage; and

increasing the power supply voltage of the power, supplied by the regulator to the load circuit, to the voltage greater than the predetermined voltage based on the control signal.