System for accurate battery run time estimation utilizing voltage capture and coulomb counting

• US 20100138176A1
• Filed: 12/02/2008
• Published: 06/03/2010
• Est. Priority Date: 12/02/2008
• Status: Abandoned Application

• Current Assignee: Avago Technologies General IP PTE Limited (Broadcom, Inc.)
• Original Assignee: Broadcom Corporation (Broadcom, Inc.)
• Inventors: Yu, Huili
• Application Number:
  US12/315,428
• Publication Number:
  US 20100138176A1
• Time in Patent Office: Days
• US Class Current: 702/63
• CPC Class Codes: G01R 31/3828 using current integration

Abstract

A disclosed embodiment is a low-cost, low-power system for run time estimation of a battery utilized by an electronic device. The system comprises a voltage capture circuit configured to measure a voltage of the battery and a coulomb counting circuit configured to measure a charge of the battery. Additionally, the voltage capture circuit is configured to measure an open-circuit voltage of the battery during a sleep mode, or battery voltage during an operation mode, and the coulomb counting circuit is configured to measure a discharge of the battery during the sleep mode, or a change or discharge of battery during an operation mode. The voltage capture circuit comprises a sample-and-hold circuit and an analog-to-digital converter, while the coulomb counting circuit comprises a sigma-delta converter, a comb filter, and a digital accumulator. The voltage capture circuit and the coulomb counting circuit are coupled through a power management unit to a microprocessor configured to estimate battery run time in the electronic device.

Claims

1. A system for accurately estimating a run time of a battery utilized by an electronic device, the system comprising:

a voltage capture circuit, said voltage capture circuit configured to measure a voltage of said battery during a sleep mode;

a coulomb counting circuit, said coulomb counting circuit configured to measure a charge of said battery.

2. The system of claim 1, wherein said voltage capture circuit is further configured to measure an open-circuit voltage of said battery.

3. The system of claim 2, wherein said voltage capture circuit is further configured to store said open-circuit voltage for utilization after said sleep mode.

4. The system of claim 1, wherein said voltage capture circuit comprises a sample-and-hold circuit.

5. The system of claim 1, wherein said voltage capture circuit comprises an analog-to-digital converter.

6. The system of claim 1, wherein said voltage capture circuit is configured to provide a voltage capture circuit output to a microprocessor of said electronic device.

7. The system of claim 1, wherein said coulomb counting circuit comprises an analog-to-digital converter.

8. The system of claim 7, wherein said analog-to-digital converter comprises a sigma-delta converter.

9. The system of claim 1, wherein said coulomb counting circuit comprises a comb filter.

10. The system of claim 1, wherein said coulomb counting circuit comprises a digital accumulator.

11. The system of claim 1, wherein said coulomb counting circuit is configured to provide a coulomb counting circuit output to a microprocessor of said electronic device.

12. The system of claim 1, further comprising a current sensor configured to provide a current signal to said coulomb counting circuit.

13. The system of claim 12, further comprising a low-pass filter configured to filter said current signal.

14. A system for accurately estimating a run time of a battery utilized by an electronic device, the system comprising:

a voltage capture circuit, said voltage capture circuit configured to measure a an open circuit voltage of said battery during a sleep mode;

a coulomb counting circuit, said coulomb counting circuit configured to measure a charge of said battery during said sleep mode.

15. The system of claim 14, wherein said voltage capture circuit is further configured to store said open-circuit voltage for utilization after said sleep mode.

16. The system of claim 14, wherein said voltage capture circuit comprises a sample-and-hold circuit.

17. The system of claim 14, wherein said voltage capture circuit comprises an analog-to-digital converter.

18. The system of claim 14, wherein said coulomb counting circuit comprises a sigma-delta converter.

19. The system of claim 14, wherein said coulomb counting circuit comprises a comb filter.

20. The system of claim 14, wherein said coulomb counting circuit comprises a digital accumulator.