Vertical bus circuits

• US 8,227,944 B2
• Filed: 12/23/2009
• Issued: 07/24/2012
• Est. Priority Date: 01/06/2009
• Status: Active Grant

• Current Assignee: O2 Micro International Limited (O2 Micro Incorporated)
• Original Assignee: O2 Micro International Limited (O2 Micro Incorporated)
• Inventors: Li, Guoxing, Liu, Liusheng
• Primary Examiner(s): Deberadinis, Robert L.
• Application Number:
  US12/645,953
• Publication Number:
  US 20110001357A1
• Time in Patent Office: 944 Days
• Field of Search: 307/150
• US Class Current: 307/150
• CPC Class Codes: G01R 31/396 Acquisition or processing of data for testing or for monitoring individual cells or groups of cells within a battery
• CPC Class Codes: H01M 10/425 Structural combination with electronic components, e.g. electronic circuits integrated to the outside of the casing printed circuits H05K1/00
• CPC Class Codes: H01M 10/482 for several batteries or cells simultaneously or sequentially
• CPC Class Codes: H01M 10/486 for measuring temperature
• CPC Class Codes: Y02E 60/10 Energy storage using batteries

Abstract

A vertical bus circuit includes multiple devices for transmitting signals between the bus devices. The multiple devices share multiple common voltage levels. Each of the devices includes a bus block and two input/output (I/O) devices powered by a first voltage level and a second voltage level of the common voltage levels, respectively. The bus block enables signal transmission between the two I/O devices, and the common voltage levels enable the signal transmission between the devices.

Claims

1. A vertical bus circuit for reduced power consumption management of a battery comprising a rechargeable multi-cell battery pack, comprising:

a plurality of bus blocks coupled to a plurality of cells in said battery and operable for transmitting signals indicating statuses of said cells between said bus blocks, wherein said bus blocks share a plurality of common voltage levels, wherein each of said bus blocks comprises a signal path, a first input/output (I/O) device, and a second I/O device, wherein said first and second input/output (I/O) devices are powered by a first common voltage level and a second common voltage level of said common voltage levels respectively, wherein said signal path enables signal transmission between said first and second I/O devices, wherein said common voltage levels enable said signal transmission between said bus blocks, and wherein said signal path comprises a differential circuit operable for transmitting said signals using a voltage difference between a first voltage and a second voltage, wherein said first and second voltages are determined by said common voltage levels.

2. The circuit of claim 1, wherein said signal path comprises an upward signal path and a downward signal path and wherein said upward signal path and said down signal path share said first and second I/O devices.

3. The circuit of claim 1, wherein each of said bus blocks is coupled to a group of cells in said battery, and wherein the voltage of at least one cell in said group of cells is used as each of said common voltage levels.

4. The circuit of claim 1, wherein each of said bus blocks is coupled to a group of cells in said battery, wherein each of said bus blocks further comprises a voltage regulator, and wherein said common voltage levels are provided by the voltage at the positive terminal of one cell in said group of cells and the output voltage of said voltage regulator.

5. A battery management system for reduced power consumption management of a battery comprising a rechargeable multi-cell battery pack, comprising:

a plurality of devices coupled to said battery having a plurality of cells, said plurality of devices operable for assessing the status of said cells, wherein each device of said plurality of devices is coupled to a group of cells of said plurality of cells, and wherein said plurality of devices use different voltages; and

a control unit coupled to a first device of said plurality of devices and operable for communicating with a destination device of said plurality of devices via said control unit, said first device, a group of devices of said plurality of devices, and said destination device, wherein said group of devices uses voltages that are between a voltage used by said first device and a voltage used by said destination device, wherein said each device of said plurality of devices comprises a differential circuit operable for transmitting a signal indicative of said status of said cells using a voltage difference between a first voltage and a second voltage, and wherein said first and second voltages are determined by said different voltages.

6. The system of claim 5, wherein said plurality of devices are powered by said plurality of cells, and wherein said first device comprises a device powered by a cell that has the lowest voltage level among said plurality of cells.

7. The system of claim 5, wherein said plurality of devices share a plurality of common voltage levels, and wherein each of said common voltage levels is configured to enable communication between a first device of said plurality of devices and a second device of said plurality of devices that share said each of said common voltage levels.

8. The system of claim 7, wherein said each device of said plurality of devices has a first and a second input/output (I/O) devices, wherein said first I/O device is powered by a first common voltage level of said common voltage levels and said second I/O device is powered by a second common voltage level of said common voltage levels.

9. The system of claim 8, wherein said each device of said plurality of devices comprises an upward signal path and a downward signal path, and wherein said upward signal path and said down signal path share said first and second I/O devices.

10. The system of claim 7, wherein said each of said common voltage levels is provided by a voltage of at least one cell in said group of cells.

11. The system of claim 7, wherein said each device of said plurality of devices comprises a voltage regulator, and wherein said common voltage levels are provided by the voltage at the positive terminal of one cell in said group of cells and the output voltage of said voltage regulator.

12. The system of claim 8, wherein said I/O devices are open-drain.

13. The system of claim 5, wherein said devices further comprise a plurality of analog-to-digital converters (ADCs) and wherein said common voltage levels are configured to diagnosis said ADCs.

14. The system of claim 5, wherein said each device of said plurality of devices comprises a bus engine, wherein said bus engine uses a default line for signal transmission, and wherein a backup line replaces said default line if said default line becomes unavailable.

15. The system of claim 5, wherein said differential circuit comprises a first switch and a second switch, and wherein said first voltage and said second voltage are a voltage at a node of said first switch and a voltage at a node of said second switch respectively.

16. A method for enabling signal transmission and enabling reduced power consumption management of a battery comprising a rechargeable multi-cell battery pack, said method comprising:

accessing statuses of cells in said battery;

transmitting a signal indicating said statuses between a first common voltage level and a second common voltage level in a first bus block of a plurality of bus blocks;

transmitting said signal by a differential circuit using a voltage difference between a first voltage and a second voltage, wherein said first voltage and said second voltage are determined by said first and second common voltage levels; and

transmitting said signal between said first bus block and a second bus block of said bus blocks, wherein said first and second bus blocks share said second common voltage level.

17. The method of claim 16, further comprising:

converting a first reference voltage to a first value using an accurate first converter;

converting said first reference voltage to a second value using a second converter; and

comparing said first value to said second value for diagnosing said second converter.

18. The method of claim 17, further comprising:

calibrating said second converter according to a result of said comparing;

converting a second reference voltage to a third value using said second converter;

converting said second reference voltage to a fourth value using a third converter; and

comparing said third value to said fourth value for diagnosing said third converter.

19. The method of claim 18, wherein said second reference voltage comprises said second common voltage level.

20. The method of claim 16, wherein said first common voltage level is used to power a first input/output (I/O) device in said first bus block, and wherein said second common voltage level is used to power a second I/O device in said first bus block.