Voltage regulation with active supplemental current for output stabilization

• US 7,372,320 B2
• Filed: 12/16/2005
• Issued: 05/13/2008
• Est. Priority Date: 12/16/2005
• Status: Active Grant

• Current Assignee: SanDisk Technologies LLC (Western Digital Corporation)
• Original Assignee: SanDisk Corporation (Western Digital Corporation)
• Inventors: Pan, Feng
• Primary Examiner(s): Richards; N. Drew
• Assistant Examiner(s): ENGLUND, TERRY LEE
• Application Number:
  US11/303,569
• Publication Number:
  US 20070139100A1
• Time in Patent Office: 879 Days
• Field of Search: None
• US Class Current: 327/541
• CPC Class Codes: G05F 1/575 characterised by the feedback circuit
• CPC Class Codes: G11C 5/147 Voltage reference generators, voltage or current regulators; Internally lowered supply levels; Compensation for voltage drops G11C5/141 takes precedence

Abstract

Techniques for efficiently stabilizing an output voltage produced by a voltage regulation circuit are disclosed. One embodiment pertains to a voltage regulation circuit that includes a supplemental current source that can be controllably activated to provide a supplemental current to an output terminal of the voltage regulation circuit. This supplemental current can then assist in stabilizing the output voltage level at the output terminal of the voltage regulation circuit even in the presence of high current surges by a load (i.e., electronic circuitry). Advantageously, given the availability of the supplemental current, the required amount of capacitance for a decoupling capacitor (also coupled to the output terminal of the voltage regulation circuit) can be significantly reduced. In the case of semiconductor electronic devices, the reduction in the needed capacitance yields substantial die area savings with respect to decoupling capacitors.

Claims

1. A voltage regulation circuit having an input terminal for receiving a supply voltage and having an output terminal, comprising:

an amplifier that receives the supply voltage and produces a regulated output voltage at the output terminal wherein said amplifier responds to a change to the regulated output voltage only after an amplifier response delay time;

a feedback circuit operatively connected to the output terminal and to a feedback terminal of said amplifier;

a decoupling capacitor operatively connected to the output terminal arranged to provide a decoupling capacitor current to the output terminal only during the amplifier response delay time; and

a supplemental current source operatively connected to the output terminal, said supplemental current source controllably providing a supplemental current to the output terminal in co-operation with the decoupling capacitor providing the decoupling capacitor current only during the amplifier response delay time thereby stabilizing the regulated output voltage by substantially eliminating a downward going voltage transition at the output terminal during the amplifier response delay time.

2. A voltage regulation circuit as recited in claim 1, wherein said supplemental current source is connected to the supply voltage.

3. A voltage regulation circuit as recited in claim 1, wherein said supplemental current source is controlled by a supplemental current source control signal.

4. A voltage regulation circuit as recited in claim 3, wherein said supplemental current source includes at least:

a current limiting device; and

a switch,

wherein said current limiting device and said switch are connected in series between the supply voltage and the output terminal.

5. A voltage regulation circuit as recited in claim 4, wherein said switch has a switching operation that operates under the control of the supplemental current source control signal.

6. A voltage regulation circuit as recited in claim 5, wherein the switching operation of said switch either permits the supplemental current to reach the output terminal or blocks the supplemental current from reaching the output terminal.

7. A voltage regulation circuit as recited in claim 3, wherein said supplemental current source includes at least:

a first current limiting device and a first switch, where said first current limiting device and said first switch are connected in series between the supply voltage and the output terminal; and

a second current limiting device and a second switch, where said second current limiting device and said second switch are connected in series between the supply voltage and the output terminal.

8. A voltage regulation circuit as recited in claim 7, wherein said first switch has a switching operation that operates under the control of a first signal of the control signal, and wherein said second switch has a switching operation that operates under the control of a second signal of the control signal.

9. A voltage regulation circuit as recited in claim 1, wherein the regulated output voltage is lower than the supply voltage.

10. A voltage regulation circuit as recited in claim 1, wherein said voltage regulation circuit is provided within a memory system, and wherein said supplemental current source is controlled to provide the supplemental current to the output terminal during an initial portion of at least one operation of the memory system.

11. A voltage regulation circuit as recited in claim 10, wherein said decoupling capacitor stores a charge that is used to provide the decoupling capacitor current to the output terminal during at least the initial portion of the at least one operation of the memory system.

12. A voltage regulation circuit as recited in claim 1, wherein said feedback circuit includes at least a capacitive divider.

13. A voltage regulation circuit having an input terminal for receiving a supply voltage and having an output terminal, comprising:

an amplifier that receives the supply voltage and produces a regulated output voltage at the output terminal wherein said amplifier responds to a change to the regulated output voltage only after an amplifier response delay time;

a decoupling capacitor operatively connected to the output terminal arranged to provide a decoupling capacitor current to the output terminal only during the amplifier response delay time;

a resistor divider operatively connected to the output terminal to provide a divided voltage to a feedback terminal of said amplifier;

a current limiter operatively connected to the supply voltage; and

a transistor operatively connected to said current limiter and to the output terminal wherein the current limiter and the transistor controllably providing a supplemental current to the output terminal in co-operation with the decoupling capacitor providing the decoupling capacitor current only during the amplifier response delay time thereby stabilizing the regulated output voltage by substantially eliminating a downward going voltage transition at the output terminal during the amplifier response delay time.

14. A voltage regulation circuit as recited in claim 13, wherein said transistor has a gate terminal, a first channel terminal and a second channel terminal, the gate terminal receiving a control signal, the first channel terminal being operatively connected to said current limiter, and the second channel terminal being operatively connected to the output terminal.

15. A voltage regulation circuit as recited in claim 14, wherein when a load connected to the output terminal induces a current draw, current to satisfy the current draw is provided, at least during an initial period, by at least said transistor and said current limiter.

16. A voltage regulation circuit as recited in claim 14, wherein when a load connected to the output terminal induces a current draw, current to satisfy the current draw is provided, at least during an initial period, by at least said decoupling capacitor as well as said transistor and said current limiter.

17. A voltage regulation circuit as recited in claim 16, wherein, subsequent to the initial period, (i) the control signal disables said transistor from providing the supplemental current to the output terminal, and (ii) said amplifier outputs current to the output terminal.

18. A voltage regulation circuit as recited in claim 13, wherein said voltage regulation circuit further comprises:

a filter capacitor operatively connected to the output terminal.

19. A voltage regulation circuit as recited in claim 13, wherein said current limiter is a resistor.

20. A memory product, comprising:

data storage elements;

a controller for performing data storage and retrieval with respect to the data storage elements; and

at least one voltage generation circuit coupled to the controller, the voltage generation circuit comprising;

an amplifier that receives a supply voltage and produces a regulated output voltage at an output terminal wherein said amplifier responds to a change to the regulated output voltage only after an amplifier response delay time;

a feedback circuit operatively connected to the output terminal and to a feedback terminal of said amplifier;

a decoupling capacitor operatively connected to the output terminal arranged to provide a decoupling capacitor current to the output terminal only during the amplifier response delay time; and

a supplemental current source operatively connected to the output terminal, said supplemental current source controllably providing a supplemental current to the output terminal in co-operation with the decoupling capacitor providing the decoupling capacitor current only during the amplifier response delay time thereby stabilizing the regulated output voltage by substantially eliminating a downward going voltage transition at the output terminal during the amplifier response delay time.

21. A memory product as recited in claim 20, wherein the memory product is a memory card.

22. A memory product as recited in claim 20, wherein the data storage elements provide non-volatile data storage.

23. A memory product as recited in claim 20, wherein the data storage elements provide semiconductor-based data storage.

24. A memory product as recited in claim 23, wherein the data storage elements are EEPROM or Flash.

25. A memory product as recited in claim 20, wherein each of the data storage elements comprise at least one floating-gate storage device.

26. A memory product as recited in claim 20, wherein the memory product is a removable data storage product.

27. A memory product as recited in claim 20, wherein the memory product is removably coupled to a host.

28. A memory product as recited in claim 27, wherein the host is a computing device.

29. An electronic system, comprising:

a data acquisition device; and

a data storage device removably coupled to the data acquisition unit, the data storage device storing data acquired by the data acquisition device, and the data storage device including at least;

data storage elements;

a controller for performing data storage and retrieval with respect to the data storage elements; and

at least one voltage generation circuit coupled to the controller, the voltage generation circuit including at least;

an amplifier that receives a supply voltage and produces a regulated output voltage at an output terminal wherein said amplifier responds to a change to the regulated output voltage only after an amplifier response delay time;

a feedback circuit operatively connected to the output terminal and to a feedback terminal of said amplifier;

a decoupling capacitor operatively connected to the output terminal arranged to provide a decoupling capacitor current to the output terminal only during the amplifier response delay time; and

a supplemental current source operatively connected to the output terminal, said supplemental current source controllably providing a supplemental current to the output terminal in co-operation with the decoupling capacitor providing the decoupling capacitor current only during the amplifier response delay time thereby stabilizing the regulated output voltage by substantially eliminating a downward going voltage transition at the output terminal during the amplifier response delay time.

30. An electronic system as recited in claim 29, wherein the data acquisition device is one of a camera, a network card or appliance, a hand-held or notebook computer, a set-top box, a hand-held or other small media player/recorder, and a medical monitor.