COMMUNICATION AND MONITORING OF A BATTERY VIA A SINGLE WIRE

• US 20160223412A9
• Filed: 12/24/2012
• Published: 08/04/2016
• Est. Priority Date: 03/07/2012
• Status: Active Grant

• Current Assignee: Apple Inc.
• Original Assignee: Apple Inc.
• Inventors: Patel, Parin, Mullins, Scott P.
• Granted Patent: US 9,797,784 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: A61K 31/56 Compounds containing cyclopenta[a]hydrophenanthrene ring systems; Derivatives thereof, e.g. steroids
• CPC Class Codes: G01K 13/00 Thermometers specially adapted for specific purposes
• CPC Class Codes: G01N 2500/00 Screening for compounds of potential therapeutic value
• CPC Class Codes: G01N 33/5041 involving analysis of members of signalling pathways
• CPC Class Codes: G06F 1/206 comprising thermal management
• CPC Class Codes: G06F 1/32 Means for saving power
• CPC Class Codes: G06F 1/3206 Monitoring of events, devices or parameters that trigger a change in power modality
• 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 10/443 in response to temperature
• CPC Class Codes: H01M 10/486 for measuring temperature
• CPC Class Codes: H01M 2010/4271 Battery management systems including electronic circuits, e.g. control of current or voltage to keep battery in healthy state, cell balancing
• CPC Class Codes: H01M 2010/4278 Systems for data transfer from batteries, e.g. transfer of battery parameters to a controller, data transferred between battery controller and main controller
• CPC Class Codes: Y02D 10/00 Energy efficient computing, e.g. low power processors, power management or thermal management
• CPC Class Codes: Y02E 60/10 Energy storage using batteries

Abstract

A power-management unit is described. This power-management unit allows a common signal line to communicate data between an integrated circuit (which may be external to the power-management unit) and a battery-monitoring mechanism in a battery pack, and to convey a signal that represents a temperature state of the battery pack to a temperature-monitoring circuit or mechanism that monitors the temperature state of the battery pack. In particular, the power-management unit may include a single-wire interface or a multiplexer that, at a given time, selectively couples the signal line from the battery pack either to the integrated circuit or the temperature-monitoring circuit based on a control signal provided by the integrated circuit (for example, via an I2C bus or interface). In this way, the power-management unit may reduce the number of signal lines needed to communicate with the battery-monitoring mechanism and to convey the signal.

Claims

1. A power-management unit, comprising:

a battery connector configured to couple to a signal line from a battery pack;

an integrated-circuit connector configured to couple to an integrated circuit that communicates with a battery-monitoring mechanism in the battery pack;

an interface circuit configured to receive a control signal from the integrated circuit;

a temperature-monitoring circuit configured to monitor a temperature state of the battery pack; and

a multiplexer, coupled to the battery connector, the integrated-circuit connector, the interface circuit, and the temperature-monitoring circuit, configured to selectively couple, based on the control signal, one of;

the battery connector and the integrated-circuit connector, and the battery connector and the temperature-monitoring circuit, so that, at a given time, the signal line conveys one of;

a signal representing the temperature state, and the communication between the integrated circuit and the battery-monitoring mechanism.

2. The power-management unit of claim 1, wherein the multiplexer periodically couples the battery connector and the temperature-monitoring circuit.

3. The power-management unit of claim 1, wherein a default condition of the multiplexer couples the battery connector and the temperature-monitoring circuit;

and

wherein the power-management unit is configured to revert to the default condition of the multiplexer a time interval after the multiplexer selectively couples the battery connector and the integrated-circuit connector.

4. The power-management unit of claim 1, wherein the integrated-circuit connector is further configured to couple to a supply voltage via a pull-up resistor so that the signal line is pulled to the supply voltage when the multiplexer selectively couples the battery connector and the integrated-circuit connector.

5. The power-management unit of claim 1, wherein, via the multiplexer, the power-management unit is configured to selectively couple the battery connector and the temperature-monitoring circuit when the battery pack is coupled to a charger.

6. The power-management unit of claim 1, wherein the temperature state indicates whether it is safe to charge the battery pack.

7. The power-management unit of claim 1, wherein the power-management unit further includes a wake circuit configured to detect a wake signal from the battery-monitoring mechanism on the signal line;

and

wherein the wake signal transitions the integrated circuit from a power saving mode to a normal operating mode.

8. The power-management unit of claim 1, wherein the temperature-monitoring circuit configured to detect a wake signal on the signal line when monitoring the temperature state;

and

wherein the wake signal transitions the integrated circuit from a power-saving mode to a normal operating mode.

9. A power-management unit, comprising a single-wire interface configured to couple to a battery pack, and based on a control signal, configured to selectively convey communication between an integrated circuit, which is external to the power-management unit, and the battery pack, and a signal representing a temperature state of the battery pack to a temperature-monitoring mechanism.

10. The power-management unit of claim 9, wherein a default configuration of the single-wire interface selectively couples the battery pack and the temperature-monitoring mechanism;

and

wherein the power-management unit is configured to revert to the default condition of the single-wire interface a time interval after the battery pack is selectively coupled to the temperature-monitoring mechanism.

11. The power-management unit of claim 9, wherein the temperature state indicates whether it is safe to charge the battery pack.

12. The power-management unit of claim 9, wherein the single-wire interface is further configured to detect a wake signal from the battery pack on the signal line;

and

wherein the wake signal transitions the integrated circuit from a power-saving mode to a normal operating mode.

13. A method for conveying a signal representing a temperature state of a battery pack and communicating data between an integrated circuit and the battery pack on a signal line, comprising:

selectively coupling, based on a control signal, the signal line to the integrated circuit that communicates with a battery-monitoring mechanism in the battery pack; and

selectively coupling, based on the control signal, the signal line to a temperature-monitoring circuit that determines a temperature state of the battery pack.

14. An electronic device, comprising:

a battery pack, wherein the battery pack includes;

a battery;

a battery-monitoring mechanism, coupled to the battery, configured to monitor characteristics of the battery;

a temperature sensor; and

a signal line coupled to the battery-monitoring mechanism and the temperature sensor;

an integrated circuit configured to provide a control signal and to communicate with the battery-monitoring mechanism; and

a power-management unit, wherein the power-management unit includes;

an interface circuit, coupled to the integrated circuit, configured to receive the control signal;

a temperature-monitoring circuit configured to monitor a temperature state of the battery pack; and

a multiplexer, coupled to the signal line, the integrated circuit, the interface circuit and the temperature-monitoring circuit, configured to selectively couple, based on the control signal, one of;

the signal line and the integrated circuit, and the signal line and the temperature-monitoring circuit, so that, at a given time, the signal line conveys a signal representing one of;

the temperature state, and the communication between the integrated circuit and the battery-monitoring mechanism.

15. The electronic device of claim 14, wherein the multiplexer periodically couples the battery pack and the temperature-monitoring circuit.

16. The electronic device of claim 14, wherein a default condition of the multiplexer couples the battery pack and the temperature-monitoring circuit;

and

wherein the power-management unit is configured to revert to the default condition of the multiplexer a time interval after the multiplexer selectively couples the battery pack and the integrated circuit.

17. The electronic device of claim 14, wherein, via the multiplexer, the power-management unit is configured to selectively couple the battery pack and the temperature-monitoring circuit when the battery pack is coupled to a charger.

18. The electronic device of claim 14, wherein the temperature state indicates whether it is safe to charge the battery pack.

19. The electronic device of claim 14, wherein the power-management unit further includes a wake circuit configured to detect a wake signal from the battery-monitoring mechanism on the signal line;

and

wherein the wake signal transitions the integrated circuit from a power-saving mode to a normal operating mode.

20. The electronic device of claim 14, wherein the temperature-monitoring circuit configured to detect a wake signal on the signal line when monitoring the temperature state;

and

wherein the wake signal transitions the integrated circuit from a power-saving mode to a normal operating mode.