Hybrid charge pump regulation

• US 7,554,311 B2
• Filed: 07/31/2006
• Issued: 06/30/2009
• Est. Priority Date: 07/31/2006
• Status: Active Grant

• Current Assignee: SanDisk Technologies LLC (Western Digital Corporation)
• Original Assignee: SanDisk Corporation (Western Digital Corporation)
• Inventors: Pan, Feng
• Primary Examiner(s): Han; Jessica
• Assistant Examiner(s): PHAM, EMILY P
• Application Number:
  US11/497,465
• Publication Number:
  US 20080024096A1
• Time in Patent Office: 1,065 Days
• Field of Search: 323/282, 323/271, 323/274, 323/275, 323/280, 323/284, 323/285, 327/536, 327/538, 327/540, 327/351
• US Class Current: 323/285
• CPC Class Codes: G11C 5/145 Applications of charge pumps; Boosted voltage circuits; Clamp circuits therefor G11C5/141 takes precedence
• 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 reliably and efficiently generating an output voltage for use within an electronic device, such as a memory system, are disclosed. A voltage generation circuit generates the output voltage. The voltage generation circuit includes regulation circuitry that controls regulation of the output voltage to maintain the output voltage at a substantially constant level. According to one aspect, regulation is provided through use of different feedback circuits. By selectively disabling one of the feedback circuits, power consumption can be reduced and the other of the feedback circuits can support the continued regulation of the output voltage. The voltage generation circuit is therefore able to operate in an accurate, stable and power efficient manner.

Claims

1. A voltage generation circuit, comprising:

a voltage producing circuit that receives an input voltage and outputs an output voltage at an output terminal, and the voltage producing circuit having a control terminal;

a comparison circuit operatively connected to the voltage producing circuit, the comparison circuit operating to compare a feedback signal received at an input terminal with a reference signal to produce a feedback signal that is supplied to the control terminal of the voltage producing circuit;

a first feedback circuit operatively connected to the output terminal of the voltage producing circuit and to the comparison circuit, the first feedback circuit providing a first feedback signal to the input terminal of the comparison circuit; and

a second feedback circuit operatively connected to the output terminal of the voltage producing circuit and to the comparison circuit, the second feedback circuit providing a second feedback signal to the input terminal of the comparison circuit, wherein the second feedback circuit can be enabled or disabled, whereby the voltage generation circuit operates with substantially reduced power when the second feedback circuit is disabled.

2. A voltage generation circuit as recited in claim 1, wherein the voltage generation circuit further comprises:

at least one switch to enable or disable operation of the second feedback circuit.

3. A voltage generation circuit as recited in claim 2, wherein the at least one switch comprises:

a first switch operatively connected between the second feedback circuit and a supply voltage; and

a second switch operatively connected between the second feedback circuit and the input terminal of the comparison circuit.

4. A voltage generation circuit as recited in claim 1, wherein the second feedback circuit can be enabled or disabled, whereby the second feedback circuit is decoupled from the comparison circuit when disabled.

5. A voltage generation circuit as recited in claim 4, wherein the voltage generation circuit further comprises:

at least one switch to enable or disable operation of the second feedback circuit.

6. A voltage generation circuit as recited in claim 4, wherein the voltage generation circuit operates with substantially reduced power when the second feedback circuit is disabled.

7. A voltage generation circuit as recited in claim 6, wherein the voltage generation circuit further comprises:

at least one switch to enable or disable operation of the second feedback circuit.

8. A voltage generation circuit as recited in claim 7, wherein the at least one switch comprises:

a first switch operatively connected between the second feedback circuit and a supply voltage; and

a second switch operatively connected between the second feedback circuit and the input terminal of the comparison circuit.

9. A voltage generation circuit as recited in claim 1, wherein the voltage generation circuit produces the output voltage for use in a memory product.

10. A voltage generation circuit as recited in claim 9, wherein the memory product is a portable memory device.

11. A voltage generation circuit, comprising:

a charge pump circuit that receives an input voltage and outputs an output voltage at an output terminal, the output voltage being derived from the input voltage, and the charge pump circuit having a control terminal;

a resistive divider operatively connected to the output terminal of the charge pump circuit to provide a first divided voltage at a first node;

a capacitor divider operatively connected to the output terminal of the charge pump circuit to provide a second divided voltage at a second node;

a comparator operatively connected to the second node and to a reference voltage, the comparator comparing the first divided voltage or the second divided voltage to the reference voltage to produce a first control signal that is supplied to the control terminal of the charge pump circuit;

a first switch operatively connected between the first node and the second node; and

a second switch operatively connected between the resistive divider and an established voltage.

12. A voltage generation circuit as recited in claim 11, wherein the resistive divider includes a plurality of resistors connected in series between the output terminal of the charge pump terminal and the second switch.

13. A voltage generation circuit as recited in claim 12, wherein the established voltage is ground.

14. A voltage generation circuit as recited in claim 12, wherein the capacitor divider includes a plurality of capacitors connected in series between the output terminal of the charge pump terminal and the established voltage.

15. A voltage generation circuit as recited in claim 11, wherein the second switch serves to prevent or substantially limit power consumption by the resistive divider when the second switch decouples the resistive divider from the established voltage.

16. A voltage generation circuit as recited in claim 11, wherein the resistive divider includes first and second resistors connected in series between the output terminal of the charge pump terminal and the second switch, and wherein the first node is a node connecting the first resistor and the second resistor.

17. A voltage generation circuit as recited in claim 16, wherein the capacitor divider includes a plurality of capacitors connected in series between the output terminal of the charge pump terminal and the established voltage, and wherein the second node is a node connecting the first capacitor and the second capacitor.

18. A voltage generation circuit as recited in claim 11, wherein the first switch and the second switch are both activated in a first phase of regulation of the output voltage by the charge pump circuit.

19. A voltage generation circuit as recited in claim 11, wherein the first switch and the second switch are both deactivated in a second phase of regulation of the output voltage by the charge pump circuit.

20. A voltage generation circuit as recited in claim 11, wherein, in a third phase of regulation, the first switch is initially activated, and subsequently the second switch is activated.

21. A voltage generation circuit as recited in claim 20, wherein the first switch is controlled by a first control signal to enable the resistor divider when regulation of the output voltage of the charge pump circuit is needed.

22. A voltage generation circuit as recited in claim 11, wherein the first switch includes at least a transistor, and wherein the second switch includes at least a transistor.

23. 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, the voltage generation circuit comprising;

a charge pump circuit that receives an input voltage and outputs an output voltage at an output terminal, the output voltage being derived from the input voltage, and the charge pump circuit having a control terminal;

a resistive divider operatively connected to the output terminal of the charge pump circuit to provide a first divided voltage at a first node;

a capacitor divider operatively connected to the output terminal of the charge pump circuit to provide a second divided voltage at a second node;

a comparator operatively connected to the second node and to a reference voltage, the comparator comparing the first divided voltage or the second divided voltage to the reference voltage to produce a first control signal that is supplied to the control terminal of the charge pump circuit;

a first switch operatively connected between the first node and the second node; and

a second switch operatively connected between the resistive divider and an established voltage.

24. A memory product as recited in claim 23, wherein the memory product is a memory card.

25. A memory product as recited in claim 23, wherein the data storage elements provide non-volatile data storage.

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

27. A memory product as recited in claim 26, wherein the data storage elements are EEPROM or FLASH.

28. A memory product as recited in claim 23, wherein each of the data storage elements comprise at least one floating-gate storage device.

29. A memory product as recited in claim 23, wherein the memory system is a removable data storage product.

30. A memory product as recited in claim 23, wherein the memory product is removably coupled to a host.

31. A memory system as recited in claim 30, wherein the host is a computing device.

32. A method for regulating a voltage level produced by a voltage generation circuit of a voltage control circuit, said method comprising:

(a) activating the voltage control circuit that produces a regulated output voltage, the voltage control circuit including at least a first feedback circuit and a comparison circuit;

(b) enabling a second feedback circuit;

(c) determining whether the output voltage has reached its regulated level; and

(d) disabling the second feedback circuit when said determining (c) determines that the output voltage has reached the regulated level, whereby regulation of the output voltage is through the second feedback circuit.

33. A method as recited in claim 32, wherein said method further comprises:

(e) subsequently determining whether there regulation of the output voltage is to be again established;

(f) enabling the second feedback circuit when said determining (e) determines that the regulation of the output voltage is to be again established;

(g) determining whether the output voltage has returned to the regulated level; and

(h) disabling the second feedback circuit when said determining (g) determines that the output voltage has returned to the regulated level.