Method and apparatus for a DC-DC charge pump voltage converter-regulator circuit

• US 6,717,458 B1
• Filed: 12/03/2001
• Issued: 04/06/2004
• Est. Priority Date: 12/03/2001
• Status: Active Grant

• Current Assignee: National Semiconductor Corporation (Texas Instruments, Inc.)
• Original Assignee: National Semiconductor Corporation (Texas Instruments, Inc.)
• Inventors: Potanin, Vladislav Y.
• Primary Examiner(s): Lam, Tuan T.
• Assistant Examiner(s): Nguyen, Hiep
• Application Number:
  US10/007,135
• Time in Patent Office: 855 Days
• Field of Search: 327/536, 327/537, 327/534, 327/390, 327/589, 327/590, 327/306, 327/331, 327/332
• US Class Current: 327/536
• CPC Class Codes: H02M 1/0022 the disturbance parameters being input voltage fluctuations
• CPC Class Codes: H02M 3/07 using capacitors charged and discharged alternately by semiconductor devices with control electrode , e.g. charge pumps

Abstract

An apparatus and method for a DC-DC charge pump voltage converter-regulator circuit includes a control circuit, a multiplier circuit, and a feedback circuit. The feedback circuit includes a load circuit, a comparator circuit, and a voltage reference circuit. The multiplier circuit produces an output signal by multiplying a supply signal according to a multiplication factor. The output signal is communicated to the load circuit. The output signal is measured producing a sense signal. The voltage reference circuit produces a reference voltage. The control circuit regulates the output signal according the result of a comparison between the sense signal and the reference voltage. In one embodiment, the multiplication factor is adjusted to compensate for a change in the supply signal. The multiplication factor may be increased to compensate for a decrease in the supply signal.

Claims

1. An apparatus for providing an output signal from a supply signal that has an associated voltage level, the apparatus comprising:

a control circuit that is configured to produce a control signal in response to the supply signal and a feedback signal that is associated with the output signal;

a first multiplier circuit receiving the control signal to produce the output signal by multiplying the supply signal according to a first multiplication factor, wherein the first multiplication factor is adjusted to compensate for a change in the supply signal;

a second multiplier circuit that is selectively coupled to the first multiplier circuit such that the first and second multiplier circuits produce the output signal in response to multiplying the supply signal by a second multiplication factor when the second multiplier circuit is coupled to the first multiplier circuit, wherein the second multiplication factor is greater than the first multiplication factor when the supply signal decreases below a predetermined level;

the feedback circuit that is configured to provide a feedback signal in response to receiving the output signal, wherein the control circuit provides regulation of the output signal in response to the feedback signal.

2. An apparatus as in claim 1, wherein the control circuit further comprises a logic circuit that is configured to produce the control signal in response to the supply signal and the feedback signal.

3. An apparatus as in claim 2, wherein the logic circuit further comprises a flip-flop circuit.

4. An apparatus as in claim 1, wherein the control circuit further comprises an oscillator circuit that is configured to produce a clock signal in response to the feedback signal, wherein the control signal is responsive to the clock signal.

5. An apparatus as in claim 1, wherein the control circuit further comprises an ADC/logic circuit that is configured to produce at least the control signal in response to the supply signal and the feedback signal.

6. An apparatus as in claim 1, wherein the first and second multiplier circuits further comprising a multiplicity of capacitance circuits, wherein the multiplicity of capacitance circuits are coupled to the supply signal during a first interval, and a selected group of the multiplicity of capacitance circuits are coupled in series with one another during a second interval such that the second multiplication factor is related to the selected group of the multiplicity of capacitance circuits.

7. An apparatus as in claim 1, the first multiplier circuit further comprising a multiplicity of capacitance circuits that are coupled to the supply signal during a first interval, and a selected group of the multiplicity of capacitance circuits that are coupled in series with one another during a second interval such that a second multiplication factor is related to the selected group of the multiplicity of capacitance circuits.

8. An apparatus as in claim 1, the feedback circuit further comprising:

a load circuit that is arranged to produce a sense signal in response to the output signal;

a voltage reference circuit that is arranged to produce a reference voltage; and

a comparator circuit that is configured to produce the feedback signal in response to a comparison between the reference voltage and the sense signal.

9. An apparatus as in claim 1, wherein the output signal is regulated to a predetermined level that is related to a reference signal by comparing at least a portion of the output signal to the reference signal.

10. A method for providing an output signal in response to a supply signal comprising:

multiplying the supply signal according to a multiplication factor to produce the output signal, wherein the multiplication factor is adjusted according to a predetermined number of capacitance circuits that are selectively coupled in series to produce the output signal, and wherein the multiplication factor corresponds to first and second multiplication factors;

measuring a sense signal that has a potential that is related to the output voltage;

comparing the sense signal to a reference signal;

regulating the output signal using a control circuit, wherein the output signal is regulated in response to the comparison of the sense signal to the reference signal; and

adjusting the first and second multiplication factors to compensate for a change in the supply signal such that the second multiplication factor is greater than the first multiplication factor when the supply signal decreases below a predetermined level.

11. A method as in claim 10, further comprising adjusting the multiplication factor according to the potential of the supply signal.

12. A method as in claim 10, wherein multiplying the supply signal further comprises coupling the predetermined number of capacitance circuits to the supply signal during a first interval and coupling the predetermined number of capacitance circuits in series during a second interval.

13. A method as in claim 12, further comprising coupling additional capacitance circuits to the supply signal during the first interval and coupling additional capacitance circuits in series with the predetermined number of capacitance circuits during the second interval to adjust the multiplication factor.

14. A method as in claim 10, further comprising adjusting the multiplication factor in response to the supply signal, wherein the multiplication factor is increased when the supply voltage decreases below a predetermined voltage level.

15. A method as in claim 14, the step of adjusting the multiplication factor further comprising coupling capacitance circuits in parallel to the supply signal such that the capacitance circuits are charged during a first interval, coupling a selected number of the capacitance circuits in series with one another during a second interval such that an output signal is provided by the selected number of capacitance circuits.

16. A method as in claim 15, the step of regulating the output signal further comprising adjusting at least one of the first and second intervals such that the output signal is maintained above a predetermined threshold level.

17. An apparatus for providing an output signal in response to a supply signal, comprising:

a means for multiplying that is arranged to multiply the supply signal according to a multiplication factor to produce the output signal, wherein the multiplication factor is adjusted according to a predetermined number of capacitance circuits selectively coupled in series to produce the output signal, and wherein the multiplication factor corresponds to first and second multiplication factors;

a means for measuring that is arranged to measure a sense signal that has a potential related to the output voltage;

a means for comparing that is arranged to compare the sense signal to a reference signal;

a means for regulating coupled to the means for multiplying to regulate the output signal using a control circuit, wherein the output signal is regulated in response to the comparison of the sense signal to reference signal; and

a means for adjusting that is arranged to adjust the first and second multiplication factors to compensate for a change in the supply signal such that the second multiplication factor is greater than the first multiplication factor when the supply signal decreases below a predetermined level.

18. An apparatus for providing an output signal from a supply signal that has an associated voltage level, the apparatus comprising:

a control circuit comprising an ADC/logic circuit that is configured to produce a control signal in response to the supply signal and a feedback signal that is associated with the output singal;

a first multiplier circuit receiving the control signal to produce the output signal by multiplying the supply signal according to a first multiplication factor, wherein the first multiplication factor is adjusted to compensate for a change in the supply signal; and

a feedback circuit that is configured to provide a feedback signal in response to receiving the output signal, wherein the control circuit provides regulation of the output signal in response to the feedback signal.