Regulator with leakage compensation

• US 6,388,506 B1
• Filed: 12/15/2000
• Issued: 05/14/2002
• Est. Priority Date: 12/15/2000
• Status: Expired due to Term

• Current Assignee: Marvell Asia Pte Limited (Marvell Technology Group Limited)
• Original Assignee: Marvell International Limited (Marvell Technology Group Limited)
• Inventors: Voo, Thart F.
• Primary Examiner(s): Cunningham, Terry D.
• Application Number:
  US09/738,715
• Time in Patent Office: 515 Days
• Field of Search: 327/534, 327/536, 327/537, 327/390
• US Class Current: 327/536
• CPC Class Codes: H02M 3/073 Charge pumps of the Schenkel-type
• CPC Class Codes: H02M 3/077 with parallel connected charge pump stages
• CPC Class Codes: H03K 17/063 in field-effect transistor switches

Abstract

The present invention provides a circuit and method for generating a regulated voltage from a voltage source. The regulator circuit includes at least two boost circuits. A first boost circuit generates a first pump voltage. The first boost circuit includes a charge pump for generating the first pump voltage from a first voltage source. The charge pump includes a charge pump switch having a leakage current. A second boost circuit generates a second pump voltage. The second boost circuit includes a charge pump for generating the second pump voltage from a second voltage source. A compensation circuit coupled between the first boost circuit and the second boost circuit supplies a compensation current to the first boost circuit to compensate for energy losses caused by the first boost circuit leakage current. An amplifier includes a reference input coupled to a reference voltage, and a sense input coupled to a sense signal representative of the first pump voltage. The amplifier is operable in response to a difference between the reference voltage and the sense signal, to control the first boost circuit output.

Claims

1. A regulator circuit for providing a regulated output voltage, comprising:

a first boost circuit to generate a first pump voltage, the first boost circuit including a first charge pump to generate the first pump voltage from a first voltage source, the first charge pump including a first charge pump switch having a first leakage current;

a second boost circuit to generate a second pump voltage, the second boost circuit including a second charge pump to generate the second pump voltage from a second voltage source;

a compensation circuit coupled between the first boost circuit and the second boost circuit to supply a compensation current to the first boost circuit to compensate for energy losses caused by the first boost circuit leakage current;

a sense circuit, responsive to the regulated output voltage, to generate the sense signal; and

an amplifier having a reference input responsive to a reference voltage, a sense input in communication the sense signal, and an output, operable in response to a difference between the reference voltage and the sense signal, to control the first and second boost circuits.

2. The regulator circuit of claim 1 further including a voltage buffer responsive to an output of the first charge pump and an output of the second charge pump such that the regulated output voltage corresponding to the first and second pump voltages is generated.

3. The regulator circuit of claim 1 wherein the first boost circuit further includes a first driver coupled to the first charge pump for generating a first drive signal to drive the first charge pump, and wherein the second boost circuit further includes a second driver coupled to the second charge pump for generating a second drive signal to drive the second charge pump.

4. The regulator circuit of claim 1 further including a driver coupled to the first and second boost circuits to generate a drive signal to drive the first and second charge pumps.

5. The regulator circuit of claim 1 wherein the compensation circuit is a reverse-biased switch.

6. The regulator circuit of claim 5 wherein the reverse-biased switch is selected from the group of diodes and FETs.

7. The regulator circuit of claim 5 wherein the reverse-biased switch is selected to have reverse-biased operating characteristics that are similar to operating characteristics associated with the charge pump switch.

8. The regulator circuit of claim 1 wherein the compensation circuit couples energy from the second boost circuit pump voltage to the first boost circuit pump voltage.

9. The regulator circuit of claim 1 wherein the compensation circuit is responsive to the first boost circuit charge pump and the second boost circuit charge pump.

10. The regulator circuit of claim 1 wherein the regulator circuit is incorporated into a semiconductor device.

11. A method for providing a regulated output voltage, comprising:

generating first and second drive signals;

generating a first pump voltage in response to the first drive signal, the first pump voltage being boosted from a first voltage source, a leakage current being associated with the first pump voltage;

generating a second pump voltage in response to the second drive signal, the second pump voltage being boosted from a second voltage source;

supplying a compensation current between the second pump voltage and the first pump voltage to compensate for energy losses caused by the leakage current;

generating a sense signal in accordance with the regulated output voltage;

generating an error signal in response to determining a difference between a reference voltage and the sense signal representative of the first pump voltage; and

controlling the drive signal in response to the error signal, whereby the first pump voltage is regulated.

12. The method of claim 11 including the step of voltage buffering the first pump voltage and the second pump voltage, whereby a buffered output voltage is generated.

13. The method of claim 11 wherein the step of supplying a compensation current includes providing a reverse-biased device coupled between the first pump voltage and the second pump voltage.

14. The method of claim 12 wherein the reverse-biased device is a diode configured device.

15. The method of claim 12 further comprising the step of filtering the first pump voltage.

16. The method of claim 12 wherein the step of generating the drive signal includes:

generating a first drive signal corresponding the first pump voltage; and

generating a second drive signal corresponding to the second pump voltage.

17. A regulator circuit for providing a regulated output voltage, comprising:

means for generating first and second drive signals;

means for generating a first pump voltage in response to the first drive signal, the first pump voltage being boosted from a first voltage source, a first leakage current being associated with the first pump voltage;

means for generating a second pump voltage in response to the second drive signal, the second pump voltage being boosted from a second voltage source;

means for supplying a compensation current between the second pump voltage and the first pump voltage to compensate for energy losses caused by the first leakage current;

means for generating, responsive to the regulated output voltage, a sense signal

means for generating an error signal in response to determining a difference between a reference voltage and a sense signal representative of the first pump voltage; and

means for controlling the drive signal in response to the error signal, whereby the first pump voltage is regulated.

18. The circuit of claim 17 further including means for voltage buffering the first and second pump voltages such that an output voltage corresponding to the first pump voltage is generated.

19. The circuit of claim 17 wherein the means for generating a drive signal generates a corresponding drive signal for driving a corresponding boost circuit.

20. The circuit of claim 17 wherein the means for generating a drive signal generates a common drive signal for driving all of the boost circuits.

21. The circuit of claim 17 wherein the means for supplying a compensation current is a reverse-biased switch.

22. The circuit of claim 21 wherein the reverse-biased switch is a diode configured device.

23. The circuit of claim 21 wherein the reverse-biased switch is selected to have reverse-biased characteristics that are similar to temperature characteristics associated with the leakage current.

24. The circuit of claim 17 wherein the means for supplying a compensation current couples energy from the second boost circuit pump voltage to the first boost circuit pump voltage.

25. The circuit of claim 17 wherein the means for supplying a compensation current couples energy from the first boost circuit charge pump to the second boost circuit charge pump.