Dynamically configurable switched capacitor power supply and method

• US 5,414,614 A
• Filed: 06/06/1994
• Issued: 05/09/1995
• Est. Priority Date: 06/06/1994
• Status: Expired due to Fees

• Current Assignee: Motorola, Inc. (Motorola Solutions, Inc.)
• Original Assignee: Motorola, Inc. (Motorola Solutions, Inc.)
• Inventors: DaBell, Steve D., Fette, Bruce A.
• Primary Examiner(s): Dougherty, Thomas M.
• Assistant Examiner(s): NGUYEN, MATTHEW VAN
• Application Number:
  US08/254,794
• Time in Patent Office: 337 Days
• Field of Search: 363/59, 363/60, 363/62, 363/74, 363/78, 363/79, 323/282, 323/283, 323/285, 307/109, 307/110, 307/482
• US Class Current: 363/59
• CPC Class Codes: H02M 3/07 using capacitors charged and discharged alternately by semiconductor devices with control electrode , e.g. charge pumps

Abstract

A dynamically configurable switched capacitor power supply and a method for operation thereof. The power supply includes a first dynamically adjustable switched capacitor network having a first input, a first output and including a first plurality of n many switched capacitors. The first input is adapted to be coupled to a power source. The first dynamically adjustable switched capacitor network provides a step-up or step-down power supply regulation function in response to first control signals. The power supply includes a control network having an error detector coupled to the first output, an oscillator for providing a clocking signal, an analog to digital conversion circuit for providing a digital representation of a voltage of the power source and control logic for providing the first control signals in response to the clocking signal and in response to signals from the error detector.

Claims

1. A dynamically configurable switched capacitor power supply comprising:

a first dynamically adjustable switched capacitor network having a first input, a first output and including a first plurality of n many switched capacitors, said first input adapted to be coupled to a power source, said first dynamically adjustable switched capacitor network for providing a step-up or step-down power supply regulation function in response to first control signals; and

a control network comprising;

an error detector coupled to said first output;

an oscillator for providing a clocking signal;

an analog to digital conversion circuit for providing a digital representation of a voltage of said power source; and

control logic for providing said first control signals in response to said clocking signal and in response to signals from said error detector.

2. A power supply as claimed in claim 1, wherein said first dynamically adjustable switched capacitor network includes n many sections, including:

a first initial section having a first initial input interconnection, a first initial output interconnection and a first initial bottom interconnection, said first initial input interconnection coupled to said first input, said first initial section comprising;

a first input switch including a first terminal coupled to said initial input interconnection;

a first initial section capacitor including a first lead coupled to a second terminal of said first input switch and a second lead coupled to said first initial bottom interconnection;

a first output switch including a first terminal coupled to said second terminal of said first input switch and a second terminal coupled to said first initial output interconnection; and

a first ground switch including a first terminal coupled to said second lead of said first initial section capacitor and a second terminal coupled to ground.

3. A power supply as claimed in claim 2, wherein said n many sections further include:

a first intermediate section including a first intermediate input interconnection coupled to said second terminal of said first input switch, a first intermediate output interconnection, a first intermediate top interconnection coupled to said first initial bottom interconnection and a first intermediate bottom interconnection, said first intermediate section comprising;

a first intermediate top switch having a first terminal coupled to said first initial bottom interconnection;

a first intermediate section capacitor having a first lead coupled to a second terminal of said first intermediate top switch and having a second lead coupled to said first intermediate bottom interconnection;

a first intermediate input switch having a first terminal coupled to said second terminal of said first input switch and having a second terminal coupled to said first lead of said first intermediate section capacitor; and

a first intermediate ground switch having a first terminal coupled to said second lead of said first intermediate section capacitor and having a second terminal coupled to ground.

4. A power supply as claimed in claim 3, wherein said n many sections further include:

a first terminal section including a first terminal top interconnection and a first terminal input interconnection, wherein said first terminal input interconnection is coupled to said second terminal of said first input switch and said first intermediate bottom interconnection is coupled to said first terminal top interconnection, said first terminal section comprising;

a terminal section capacitor having a first lead and having a second lead coupled to ground;

a terminal top switch having a first terminal coupled to said terminal top interconnection and having a second terminal coupled to said second lead of said terminal section capacitor; and

a terminal input switch having a first terminal coupled to said terminal input interconnection and having a second terminal coupled to said second lead of said terminal section capacitor.

5. A power supply as claimed in claim 1, further comprising:

a second dynamically adjustable switched capacitor network having a second input, a second output and including a second plurality of m many switched capacitors, said second input coupled to said first output, said second dynamically adjustable switched capacitor network for providing a step-up or step-down power supply regulation function in response to second control signals; and

wherein said control network comprises control logic for providing said second control signals.

6. A power supply as claimed in claim 5, wherein said second dynamically adjustable switched capacitor network includes m many sections, including:

a second initial section having a second initial input interconnection, a second initial output interconnection and a second initial bottom interconnection, said second initial input interconnection coupled to said second input;

a second intermediate section including a second intermediate input interconnection coupled to said second input, a second intermediate output interconnection, a second intermediate top interconnection coupled to said second initial bottom interconnection and a second intermediate bottom interconnection; and

a second terminal section including a second terminal top interconnection and a second terminal input interconnection, wherein said second intermediate bottom interconnection is coupled to said second terminal top interconnection.

7. A power supply as claimed in claim 6, wherein said second initial section comprises:

a second input switch including a first terminal coupled to said second initial input interconnection, wherein said second terminal input interconnection is coupled to a second terminal of said second input switch;

a second initial section capacitor including a first lead coupled to a second terminal of said second input switch and a second lead coupled to said second initial bottom interconnection;

a second output switch including a first terminal coupled to said second terminal of said second input switch and a second terminal coupled to said second initial output interconnection; and

a ground switch including a first terminal coupled to said second lead of said second initial section capacitor and a second terminal coupled to ground.

8. A power supply as claimed in claim 6, wherein said second intermediate section comprises:

a second intermediate top switch having a first terminal coupled to said second initial bottom interconnection;

a second intermediate section capacitor having a first lead coupled to a second terminal of said second intermediate top switch and having a second lead coupled to said second intermediate bottom interconnection;

a second intermediate input switch having a first terminal coupled to said second terminal of said second input switch and having a second terminal coupled to said first lead of said second intermediate section capacitor; and

a second intermediate ground switch having a first terminal coupled to said second lead of said second intermediate section capacitor and having a second terminal coupled to ground.

9. A power supply as claimed in claim 6, wherein said second terminal section comprises:

a second terminal section capacitor having a first lead and having a second lead coupled to ground;

a second terminal top switch having a first terminal coupled to said second terminal top interconnection and having a second terminal coupled to said second lead of said second terminal section capacitor; and

a second terminal input switch having a first terminal coupled to said second terminal input interconnection and having a second terminal coupled to said second lead of said second terminal section capacitor.

10. A power supply as claimed in claim 1, wherein said oscillator comprises a voltage controlled oscillator coupled to said error detector, said voltage controlled oscillator providing first control signals having an increased clocking frequency when said error detector detects that an output voltage decreases below a first predetermined limit and for providing first control signals having a reduced clocking frequency when said error detector detects that an output voltage increases above a second predetermined limit.

19. A power supply as claimed in claim 1, wherein said first dynamically adjustable switched capacitor network and said control network comprise a very large scale integrated circuit.

11. In a dynamically configurable switched capacitor power supply comprising a first dynamically adjustable switched capacitor network having a first input, a first output and including a first plurality of n many switched capacitors, said first input adapted to be coupled to a power source, said first dynamically adjustable switched capacitor network responsive to first control signals, and a control network comprising an error detector coupled to said first output, an oscillator for providing a clocking signal, an analog to digital conversion circuit for providing a digital representation of a voltage of said power source, and control logic for providing said first control signals in response to said clocking signal and in response to signals from said error detector, a method for providing step-up or step-down regulation, said method comprising steps of:

comparing an output voltage to a predetermined desired value;

increasing a frequency of said oscillator when said output voltage is less than said predetermined desired value by a first predetermined amount; and

decreasing a frequency of said oscillator when said output voltage is greater than said predetermined desired value by a second predetermined amount.

12. A method as claimed in claim 11, further comprising steps of:

comparing an input voltage to a desired output voltage to determine a ratio of input voltage to desired output voltage;

determining when said input voltage is greater than an output voltage;

setting said first dynamically adjustable switched capacitor network to perform a step-down function when said input voltage is greater than said output voltage; and

setting said first dynamically adjustable switched capacitor network to perform a step-up function when said input voltage is less than said desired output voltage.

13. A method as claimed in claim 11, wherein said first dynamically adjustable switched capacitor network comprises an initial section having an initial input interconnection, an initial output interconnection and an initial bottom interconnection, said initial input interconnection coupled to said input an intermediate section including an intermediate input interconnection coupled to a second terminal of said input switch, an intermediate output interconnection, an intermediate top interconnection coupled to said initial bottom interconnection and an intermediate bottom interconnection, and a terminal section including a terminal top interconnection and a terminal input interconnection, wherein said terminal input interconnection is coupled to said second terminal of said input switch and said intermediate bottom interconnection is coupled to said terminal top interconnection, further comprising steps of:

comparing an input voltage to a desired output voltage to determine a ratio of input voltage to desired output voltage;

determining a number between one and n approximating said ratio; and

turning off said terminal section when said number is less than n.

14. A method as claimed in claim 13, further comprising a step of turning off said intermediate section when said number is less than n minus one.

15. A method as claimed in claim 13, wherein said terminal section comprises a terminal section capacitor having a first lead and having a second lead coupled to ground a terminal top switch having a first terminal coupled to said terminal top interconnection and having a second terminal coupled to said second lead of said terminal section capacitor, and a terminal input switch having a first terminal coupled to said terminal input interconnection and having a second terminal coupled to said second lead of said terminal section capacitor, and wherein said intermediate section comprises an intermediate top switch having a first terminal coupled to said initial bottom interconnection, an intermediate section capacitor having a first lead coupled to a second terminal of said intermediate top switch and having a second lead coupled to said intermediate bottom interconnection, an intermediate input switch having a first terminal coupled to said second terminal of said input switch and having a second terminal coupled to said first lead of said intermediate section capacitor and an intermediate ground switch having a first terminal coupled to said second lead of said intermediate section capacitor and having a second terminal coupled to ground, wherein said step of turning off said terminal section when said number is less than n comprises steps of:

setting said intermediate ground switch to a conductive state;

setting said terminal input switch to a nonconductive state; and

setting said terminal top switch to a

nonconductive state.

16. A method as claimed in claim 11, wherein said first dynamically adjustable switched capacitor network and said control network comprise a very large scale integrated circuit.

17. A method as claimed in claim 11, wherein said dynamically configurable switched capacitor power supply further comprises a second dynamically adjustable switched capacitor network having a second input coupled to said first output, a second output and including a second plurality of m many switched capacitors, said second input adapted to be coupled to a power source, said second dynamically adjustable switched capacitor network responsive to second control signals, said method further comprising steps of:

supplying clocking signals of a first phase to said first dynamically configurable switched capacitor power supply; and

supplying clocking signals of a second phase to said second dynamically configurable switched capacitor power supply, wherein said clocking signals of said second phase are complementary to said clocking signals of said first phase.

18. A dynamically configurable switched capacitor power supply comprising:

a first dynamically adjustable switched capacitor network having a first input, a first output and including a first plurality of n many switched capacitors, said first input adapted to be coupled to a power source, said first dynamically adjustable switched capacitor network for providing a step-up or step-down power supply regulation function in response to first control signals comprising first clocking signals;

a second dynamically adjustable switched capacitor network having a second input coupled to said first output, a second output and including a second plurality of n many switched capacitors, said second input adapted to be coupled to a power source, said second dynamically adjustable switched capacitor network for providing a step-up or step-down power supply regulation function in response to second control signals, wherein said second control signals comprise second clocking signals complementary in phase to said first clocking signals; and

a control network comprising;

an error detector coupled to said second output;

an oscillator for providing a clocking signal;

an analog to digital conversion circuit for providing a digital representation of a voltage of said power source; and

control logic for providing said first and second control signals in response to said clocking signal and in response to signals from said error detector.