System and method for extracting energy from an ultracapacitor

• US 7,541,782 B2
• Filed: 03/30/2004
• Issued: 06/02/2009
• Est. Priority Date: 03/30/2004
• Status: Active Grant

• Current Assignee: Intel Corporation
• Original Assignee: Intel Corporation
• Inventors: Narendra, Siva G., Borkar, Shekhar Y.
• Primary Examiner(s): Tso; Edward
• Assistant Examiner(s): BOATENG, ALEXIS ASIEDUA
• Application Number:
  US10/811,806
• Publication Number:
  US 20050219784A1
• Time in Patent Office: 1,890 Days
• Field of Search: 320/166, 320/167, 320/164, 320/162
• US Class Current: 320/167
• CPC Class Codes: H01C 3/20 wound on cylindrical or prismatic base H01C3/16 takes precedence
• CPC Class Codes: H01G 9/14 Structural combinations or circuits for modifying, or compensating for, electric characteristics of electrolytic capacitors
• CPC Class Codes: H01L 23/5222 Capacitive arrangements or effects of, or between wiring layers other capacitive arrangements H01L23/642
• CPC Class Codes: H01L 2924/00 Indexing scheme for arrangements or methods for connecting or disconnecting semiconductor or solid-state bodies as covered by H01L24/00
• CPC Class Codes: H01L 2924/0002 Not covered by any one of groups H01L24/00, H01L24/00 and H01L2224/00
• CPC Class Codes: H02J 2207/20 Charging or discharging characterised by the power electronics converter
• CPC Class Codes: Y02E 60/13 Energy storage using capacitors

Abstract

An extraction system detects a voltage stored in a capacitor and then extracts energy from the capacitor when the voltage falls below a predetermined value. The capacitor may be an ultracapacitor formed in silicon or another semiconductor material, and the predetermined value may equal or be based on a minimum operating voltage of a load driven by the ultracapacitor. Once the energy is extracted, the system converts the energy into a voltage sufficient to continue driving the load. Energy extraction may be performed by a variety of circuits including a linear regulator, a switched capacitor voltage converter, an adiabatic amplifier, and a DC-to-DC boost converter. The system may further include a monitoring circuit which detects dynamic changes in the converted ultracapacitor voltage over to maintain the operating voltage of the load.

Claims

1. A system, comprising:

a detector to detect a voltage stored in an ultracapacitor coupled to a load; and

an extractor to extract energy from the ultracapacitor, the extractor including;

a first amplifier circuit to amplify an output voltage from the ultracapacitor when the detected voltage falls below a first predetermined voltage;

a divider to divide the amplified voltage to form a first control signal for the first amplifier circuit; and

a controller to generate a second control signal to vary a ratio of the divider, the varied ratio adjusting the first control signal to maintain the output voltage of the ultracapacitor substantially equal to or above the first predetermined voltage, the first amplifier circuit to amplify the output voltage independent of coupling the ultracapacitor to a DC power source during a charging operation of the ultracapacitor and during a time when the load is to be driven based on the amplified output voltage, and wherein an operation is to be performed to prevent the first amplifier circuit from amplifying the output voltage of the ultracapacitor when the detected voltage is above the first predetermined voltage.

2. The system of claim 1, wherein the first amplifier circuit is to amplify said output voltage of the ultracapacitor to a level substantially equal to or above the first predetermined voltage during a time when the detected voltage of the ultracapacitor is above a second predetermined voltage of the first amplifier circuit.

3. The system of claim 1, further comprising:

a second amplifier circuit to adjust impedance of the amplified voltage output from the first amplifier circuit.

6. The system of claim 1, wherein the extractor is a DC-to-DC boost converter.

14. The system of claim 2, wherein the first predetermined voltage corresponds to a minimum operating voltage of the load.

15. The system of claim 14, wherein the second predetermined voltage corresponds to a minimum operating voltage of the first amplifier circuit.

16. The system of claim 15, wherein the extractor is disabled when a voltage of the voltage source falls below a second predetermined voltage of the extractor.

17. The system of claim 16, wherein the first predetermined voltage corresponds to a minimum operating voltage of the load.

18. The system of claim 17, wherein the second predetermined voltage corresponds to a minimum operating voltage of the extractor.

19. The system of claim 2, wherein the extractor is disabled when the detected voltage of the ultracapacitor falls below the second predetermined voltage of the first amplifier circuit.

20. The system of claim 1, wherein the ultracapacitor is to be coupled to the load along a first signal path when the detected voltage is above the first predetermined voltage and wherein the ultracapacitor is to be coupled to the load along a second signal path passing through the extractor and disconnected from the first signal path when the detected voltage is below the first predetermined voltage.

21. The system of claim 1, wherein the divider includes a network of variable resistors.

22. The system of claim 21, wherein the second control signal is to vary values of the variable resistors to change amplification of the first amplifier circuit, the changed amplification causing the output voltage of the ultracapacitor to be substantially equal to or above the first predetermined voltage of the load.

23. The system of claim 1, wherein the ratio of the divider is continuously changed by the controller as the detected voltage of the ultracapacitor changes over time.

4. A system, comprising:

a detector to detect a voltage stored in an ultracapacitor coupled to a load; and

an extractor to extract energy from the ultracapacitor, the extractor including;

an adiabatic amplifier to amplify voltage output from the ultracapacitor when the detected voltage falls below a first predetermined voltage, wherein the adiabatic amplifier includes;

first and second transmission gates that are alternatively switched to output an amplified differential signal that corresponds to the amplified voltage of the ultracapacitor, wherein the adiabatic amplifier is to amplify the voltage output from the ultracapacitor independent of coupling the ultracapacitor to a DC power source during a charging operation of the ultracapacitor and during a time when the load is to be driven based on the amplified output voltage, and wherein an operation is to be performed to prevent the adiabatic amplifier from amplifying the output voltage of the ultracapacitor when the detected voltage is above the first predetermined voltage.

5. The system of claim 4, further comprising:

a controller to monitor a change in the amplified voltage; and

a voltage regulator to adjust the amplified differential signal to cause the amplified voltage of the ultracapacitor to be substantially equal to or above the first predetermined voltage.

7. A method, comprising:

detecting a voltage stored in an ultracapacitor coupled to a load; and

extracting energy from the ultracapacitor when the voltage falls below a predetermined value, said extracting including;

amplifying an output voltage from the ultracapacitor using a first amplifier circuit, the output voltage amplified when the detected voltage falls below a first predetermined voltage;

dividing the amplified voltage using a divider to form a first control signal for the first amplifier circuit; and

generating a second control signal to vary a ratio of the divider, the varied ratio adjusting the first control signal to maintain the output voltage of the ultracapacitor substantially equal to or above the first predetermined voltage, the first amplifier circuit to amplify said output voltage independent of coupling the ultracapacitor to a DC power source during a charging operation of the ultracapacitor and during a time when the load is to be driven based on the amplified output voltage, said method further comprising;

performing an operation to prevent the first amplifier circuit from amplifying the output voltage of the ultracapacitor when the detected voltage is above the first predetermined voltage.

8. The method of claim 7, wherein the varied ratio adjusts the first control signal to maintain the output voltage of the ultracapacitor substantially equal to or above the first predetermined voltage during a time when the detected voltage of the ultracapacitor is above a second predetermined voltage of an amplifier circuit that is to perform said amplifying.

9. The method of claim 8, further comprising:

detecting a reduction in the increased voltage over time; and

adjusting the reduced voltage to maintain at least the predetermined voltage of the load.

10. The method of claim 7, wherein said amplifying is performed by a circuit which includes an adiabatic amplifier.

11. A system, comprising:

a load;

an ultracapacitor storing a voltage to drive the load; and

an extractor to extract energy from the ultracapacitor, the extractor including;

a first amplifier circuit to amplify an output voltage from the ultracapacitor when the detected voltage falls below a first predetermined voltage,

a divider to divide the amplified voltage to form a first control signal for the first amplifier circuit; and

a controller to generate a second control signal to vary a ratio of the divider, the varied ratio adjusting the first control signal to maintain the output voltage of the ultracapacitor substantially equal to or above the first predetermined voltage, the first amplifier circuit to amplify said output voltage independent of coupling the ultracapacitor to a DC power source during a charging operation of the ultracapacitor and during a time when the load is to be driven based on the amplified output voltage, and wherein an operation is to be performed to prevent the first amplifier circuit from amplifying the output voltage of the ultracapacitor when the detected voltage is above the first predetermined voltage.

12. The system of claim 11, wherein the load is at least one of a power supply, processor, cache, chipset, and a memory.

13. The system of claim 11, wherein the load, ultracapacitor, and extractor are included on a single die.