PATENT DOCUMENT

Publication Number: US-9797784-B2
Application Number: US-201213726503-A
Country: US
Kind Code: B2

Title: Communication and monitoring of a battery via a single wire

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:
What is claimed is: 
     
       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 located in the battery pack; 
 an interface circuit configured to receive a control signal from the integrated circuit; 
 a temperature-monitoring circuit external to the battery pack and configured to monitor a temperature state of the battery pack via the signal line; 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 first time, the signal line conveys a signal representing the temperature state and at a second time the signal line conveys 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 place the multiplexer in the default condition after a predetermined interval of time has elapsed since the multiplexer&#39;s selectively coupling 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, the wake circuit coupled to the integrated-circuit connector, and coupleable to the battery-monitoring mechanism via the signal line,
 wherein the wake circuit is configured to detect a wake signal from the battery-monitoring mechanism on the signal line and upon such detection, cause the integrated circuit to transition from a power-saving mode to a normal operating mode. 
 
     
     
       8. The power-management unit of  claim 1 , wherein the temperature-monitoring circuit is configured to detect a wake signal on the signal line when monitoring the temperature state of the battery pack, and upon such detection, cause the integrated circuit to transition from a power-saving mode to a normal operating mode. 
     
     
       9. 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, the method comprising:
 receiving a control signal from the integrated circuit; 
 selectively coupling, based on the control signal, the signal line to the integrated circuit that communicates with a battery-monitoring mechanism inside the battery pack; and 
 selectively coupling, based on the control signal, the signal line to a temperature-monitoring circuit external to the battery pack that determines a temperature state of the battery pack; 
 such that at a first time, the signal line conveys a signal representing the temperature state and at a second time the signal line conveys the communication between the integrated circuit and the battery-monitoring mechanism. 
 
     
     
       10. An electronic device, comprising:
 a battery pack, wherein the battery pack includes:
 a battery; 
 a battery-monitoring mechanism, coupled to the battery, located in the battery pack and 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 via the signal line; 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 first time, the signal line conveys a signal representing the temperature state and at a second time the signal line conveys a signal representing the communication between the integrated circuit and the battery-monitoring mechanism. 
 
 
     
     
       11. The electronic device of  claim 10 , wherein the multiplexer periodically couples the battery pack and the temperature-monitoring circuit. 
     
     
       12. The electronic device of  claim 10 ,
 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 place the multiplexer in the default condition after a predetermined amount of time has passed since the multiplexer selectively coupled the battery pack and the integrated circuit. 
 
     
     
       13. The electronic device of  claim 10 , 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. 
     
     
       14. The electronic device of  claim 10 , wherein the temperature state indicates whether it is safe to charge the battery pack. 
     
     
       15. The electronic device of  claim 10 , wherein the power-management unit further includes a wake circuit, the wake circuit coupled to the integrated-circuit connector, and coupleable to the battery-monitoring mechanism via the signal line,
 wherein the wake circuit is configured to detect a wake signal from the battery-monitoring mechanism on the signal line and upon such detection, cause the integrated circuit to transition from a power-saving mode to a normal operating mode. 
 
     
     
       16. The electronic device of  claim 10 , wherein the temperature-monitoring circuit is configured to detect a wake signal on the signal line when monitoring the temperature state and upon such detection transition the integrated circuit from a power-saving mode to a normal operating mode. 
     
     
       17. The power-management unit of  claim 1  wherein the signal representing the temperature state is an analog signal and wherein the communication between the integrated circuit and the battery-monitoring mechanism is digital communication. 
     
     
       18. The method of  claim 9  wherein the signal representing a temperature state of the battery pack is an analog signal and the data communicated between the integrated circuit and the battery pack is digital data. 
     
     
       19. The electronic device of  claim 10  wherein the signal representing the temperature state is an analog signal and the signal representing the communication between the integrated circuit and the battery-monitoring mechanism is a digital signal.

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
     This application claims priority under 35 U.S.C. §119(e) to U.S. Provisional Application Ser. No. 61/607,911, entitled “Communication and Monitoring of a Battery Via a Single Wire,” by Parin Patel and Scott P. Mullins, filed on Mar. 7, 2012, the contents of which is herein incorporated by reference. 
     This application is also related to: U.S. Patent Application Ser. No. 61/607,916, entitled “Charging a Battery Based on Stored Battery Characteristics,” by Parin Patel and Scott P. Mullins, filed Mar. 7, 2012, the contents of which are herein incorporated by reference. 
    
    
     BACKGROUND 
     Field 
     The described embodiments relate to techniques for monitoring and communicating with a battery pack. More specifically, the described embodiments relate to techniques for communicating data and a signal representing a temperature state of the battery pack via a common signal line. 
     Related Art 
     The ever-increasing functionality and performance of portable electronic devices is, in part, due to advances in power sources, such as battery packs. Modern battery packs in portable electronic devices typically include circuits that monitor characteristics of the battery packs, for example, the voltage across a battery in a battery pack, a charging current, an internal impedance, the available capacity, etc. This information is typically communicated to a host portable electronic device via one or more signal lines. 
     In addition, for safety reasons, it is often important to at least periodically monitor the temperature of a battery pack. For example, the temperature of the battery pack may be monitored during charging. The temperature of the battery pack is typically conveyed to a host portable electronic device via a separate signal line from the one used to convey the other characteristics of the battery pack. 
     However, having separate signal lines to convey the battery pack characteristics and the temperature consumes valuable area or real estate in portable electronic devices, thereby increasing the cost. In addition, these separate signal lines increase the complexity and the power consumption in portable electronic devices. 
     SUMMARY 
     The described embodiments include a power-management unit that 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 to the temperature-monitoring circuit based on a control signal (such as a timing 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. 
     The temperature state may indicate whether it is safe to charge the battery pack. Therefore, the power-management unit may selectively couple the battery pack and the temperature-monitoring circuit when the battery pack is coupled to a charger. Furthermore, for safety reasons the selective coupling to the temperature-monitoring circuit may be periodic. In addition, this coupling may be a default configuration or condition of the multiplexer, and the power-management unit may revert to this default condition a time interval after the multiplexer selectively couples the battery pack and the integrated circuit. In this way, the temperature state of the battery pack can be monitored even if the control signal is not provided by the integrated circuit. 
     In some embodiments where a host (e.g., the integrated circuit) is in a power-saving mode (such as a ‘sleep’ mode), the signal line can be used to convey a wake signal from the battery-monitoring mechanism to transition the host to a normal operating mode. Because this wake signal can be conveyed when either the integrated circuit or the temperature-monitoring circuit is selectively coupled to the battery pack, the wake signal may be detected by a wake circuit in the power-management unit and/or by the temperature-monitoring circuit. 
     In some embodiments, when the multiplexer selectively couples the signal line to the integrated circuit, the signal line is also coupled to a supply voltage via a pull-up resistor so that the signal line is pulled to the supply voltage. 
     Another embodiment provides an electronic device that includes the battery pack, the integrated circuit and the power-management unit, which is coupled to the battery pack by the signal line. This battery pack may include: a battery; the battery-monitoring mechanism that monitors characteristics of the battery; a temperature sensor; and the signal line, which is electrically coupled to the battery-monitoring mechanism and the temperature sensor. 
     Another embodiment provides a method for conveying the signal that represents the temperature state of the battery pack and communicating data between the integrated circuit and the battery pack on the signal line, which may be performed by the power-management unit. Based on the control signal, the power-management unit selectively couples the signal line to the integrated circuit that communicates with the battery-monitoring mechanism in the battery pack. Subsequently, based on the control signal, the power-management unit selectively couples the signal line to the temperature-monitoring circuit that determines the temperature state of the battery pack. 
    
    
     
       BRIEF DESCRIPTION OF THE FIGURES 
         FIG. 1  presents a block diagram illustrating an electronic device that includes a power-management unit, an integrated circuit and a battery pack in accordance with an embodiment of the present disclosure. 
         FIG. 2  presents a block diagram illustrating a power-management unit in the electronic device of  FIG. 1  in accordance with an embodiment of the present disclosure. 
         FIG. 3  presents a block diagram illustrating operation of the power-management unit of  FIG. 2  in accordance with an embodiment of the present disclosure. 
         FIG. 4  presents a block diagram illustrating operation of the power-management unit of  FIG. 2  in accordance with an embodiment of the present disclosure. 
         FIG. 5  presents a timing diagram illustrating operation of the power-management unit of  FIG. 2  in accordance with an embodiment of the present disclosure. 
         FIG. 6  presents a flowchart illustrating a method for conveying a signal that represents a temperature state of a battery pack and communicating data between an integrated circuit and the battery pack on a signal line in accordance with an embodiment of the present disclosure. 
     
    
    
     Note that like reference numerals refer to corresponding parts throughout the drawings. Moreover, multiple instances of the same part are designated by a common prefix separated from an instance number by a dash. 
     DETAILED DESCRIPTION 
       FIG. 1  presents a block diagram illustrating an electronic device  100  that includes a power-management unit  110 , an integrated circuit  112  (such as a processor, a graphics processor and/or a system-on-chip) and a battery pack  114 . Battery pack  114  may include: a battery  116  that provides power to electronic device  100  via connectors  118 ; a battery-monitoring mechanism or BMM  120  (such as control logic and/or firmware, which is sometimes collectively referred to as a ‘gas gauge’) that monitors one or more physical characteristics of battery pack  114  and/or battery  116  (such as a voltage, a current, an internal impedance, a capacity, a charging time, etc.); a temperature sensor  122  (such as a thermistor) that measures a temperature of battery pack  114  and/or battery  116 ; and a signal line  124 , which electrically couples battery-monitoring mechanism  120  and temperature sensor  122  to power-management unit  110 . 
     Note that battery pack  114  is electrically coupled to a remainder of electronic device  100  by three signal lines (instead of four), including those associated with power and ground connectors  118  (which are not shown for clarity) and signal line  124  (which, as described below, combines temperature monitoring and data communication). As a consequence, an area in electronic device  100  needed to interface with battery pack  114  is reduced, thereby reducing the cost and complexity of battery pack  114  and electronic device  100 . 
     This reduction in the number of signal lines is facilitated by alternating use of signal line  124  to communicate data between battery-monitoring mechanism  120  and integrated circuit  112 , and to convey a signal from temperature sensor  122  that represents a temperature (and, more generally, a temperature state) of battery pack  114  and/or battery  116 . This sharing of signal line  124  is facilitated by power-management unit  110 . In particular, power management unit  110  may include a single-wire interface (SWI)  126 . In the discussion that follows, single-wire interface  126  is illustrated by a multiplexer, and integrated circuit  112  implements a single-wire communication protocol, such as HDQ serial data interface (from Texas Instruments, Inc. of Dallas, Tex.), on signal line  128  for use in communicating data with battery-monitoring mechanism  120 . (However, in other embodiments single-wire interface  126  implements the single-wire communication protocol.) 
       FIG. 2  presents a block diagram illustrating power-management unit  110  ( FIG. 1 ). Power-management unit  110  includes: battery connector  210  electrically coupled to signal line  124  ( FIG. 1 ); an integrated-circuit (IC) connector  212  electrically coupled to integrated circuit  112  via signal line  128  ( FIG. 1 ); an interface circuit  214  that receives a control signal (such as a timing signal) from integrated circuit  112  in  FIG. 1  via interface connectors  208  (and, more generally, one or more instructions, commands or signals that are used to control multiplexer  218 ); a temperature-monitoring circuit  216  (or a temperature-monitoring mechanism) that monitors a temperature state of battery pack  114  and/or battery  116  in  FIG. 1 ; and multiplexer  218 . For example, the control signal may be received via an I2C bus or interface (from NXP Semiconductors, Inc. of Eindhoven, The Netherlands). However, a wide variety of communication techniques and protocols can be used to convey the control signal from integrated circuit  112  ( FIG. 1 ) to power-management unit  110 , such as a Serial Peripheral Interface Bus. Furthermore, as illustrated in  FIG. 2 , temperature-monitoring circuit  216  may include a current source  220  that drives a current through temperature sensor  122  ( FIG. 1 ) and a buffer or an amplifier  222  (such as an operational amplifier) that outputs the resulting voltage that was on signal line  124  ( FIG. 1 ). 
     Based on the control signal, multiplexer  218  selectively couples one of: battery connector  210  and integrated-circuit connector  212 , and battery connector  210  and temperature-monitoring circuit  216 . In this way, at a given time, signal line  124  ( FIG. 1 ) conveys one of: a signal representing the temperature state, and the communication between integrated circuit  112  ( FIG. 1 ) and battery-monitoring mechanism  120  ( FIG. 1 ). Thus, power-management unit  110  may facilitate a reduction in the number of connectors and signal lines used to interface with battery pack  114  ( FIG. 1 ). 
     Note that the temperature state may indicate whether it is safe to charge battery  116  in battery pack  114  ( FIG. 1 ). Therefore, the temperature state may include an absolute or relative temperature of battery pack  114  and/or battery  116  ( FIG. 1 ), which may be represented by the voltage output by amplifier  222 . For example, in embodiments where temperature sensor  122  ( FIG. 1 ) includes a thermistor, the resistance may vary between approximately 2 and 50 kΩ depending on the temperature of battery pack  114  and/or battery  116  ( FIG. 1 ). In these embodiments, the voltage output by amplifier  222  may vary between 0.1 and 2.5 V. (Thus, the temperature state may be determined based on an analog signal provided by temperature sensor  122  in  FIG. 1 .) However, in other embodiments temperature-monitoring circuit  216  includes digital logic that converts the signal on signal line  124  ( FIG. 1 ) into a digital value(s) that represents the temperature state. In these embodiments, the temperature state may include: a thermal condition of battery pack  114  and/or battery  116  ( FIG. 1 ), such as ‘safe to charge’ or ‘unsafe to charge’; and/or a constraint on the charging of battery pack  114  and/or battery  116  ( FIG. 1 ) based on the temperature state (such as a charging current that may not exceed 800, 900 or 1000 mA). 
     Referring back to  FIG. 1 , as a consequence of these safety considerations, power-management unit  110  may selectively couple battery pack  114  and temperature-monitoring circuit  216  ( FIG. 2 ) when battery pack  114  is coupled to a charger  130  (which receives power from an adapter  132  that can convert household alternating current (AC) electricity into direct current (DC) electricity for use by electronic device  100 ). (In  FIG. 1 , a return path to charger  130  may be provided via GND in electronic device  100 .) As described further below with reference to  FIG. 5 , for safety reasons the selective coupling to the temperature-monitoring circuit  216  ( FIG. 2 ) may be periodic (in this way, even in the event of a hardware or software failure in integrated circuit  112 , the temperature state of battery pack  114  and/or battery  116  can continue to be monitored for a potentially unsafe condition). In addition, the coupling of battery pack  114  and temperature-monitoring circuit  216  ( FIG. 2 ) may be a default configuration or condition of multiplexer  218  ( FIG. 2 ), and power-management unit  110  may revert to this default condition a time interval (such as 500 ms) after multiplexer  218  ( FIG. 2 ) selectively couples battery pack  114  and integrated circuit  112 . In this way, the temperature state of battery pack  114  and/or battery  116  can be monitored even if the control signal is not provided by integrated circuit  112 . 
     Note that signal line  128  coupling integrated circuit  112  and power-management unit  110  may be electrically coupled to a supply voltage (such as 1.8 V) via a pull-up resistor so that signal line  124  is pulled to the supply voltage when multiplexer  218  ( FIG. 2 ) selectively couples integrated circuit  112  and battery pack  114 . 
     In some embodiments where a host (e.g., integrated circuit  112 ) is in a power-saving mode (such as a ‘sleep’ mode), signal line  124  can be used to convey a wake signal from battery-monitoring mechanism  120  to transition the host to a normal operating mode (i.e., in embodiments where battery-monitoring mechanism  120  is temporarily a ‘master’ and integrated circuit  112  is temporarily a ‘slave,’ signal line  124  may be used to indicate that a condition has occurred, such as a low battery voltage, where battery-monitoring mechanism  120  wants to wake integrated circuit  112  and make it the master). Because this wake signal can be conveyed when either integrated circuit  112  or temperature-monitoring circuit  216  ( FIG. 2 ) is selectively coupled to battery pack  114 , the wake signal may be detected by a wake circuit in power-management unit  110  and/or by temperature-monitoring circuit  216  ( FIG. 2 ). 
     This is shown in  FIG. 2 . In particular, power-management unit  110  may include a wake circuit  224  that detects the wake signal when multiplexer  218  selectively couples integrated circuit  112  ( FIG. 1 ) to battery pack  114  ( FIG. 1 ). For example, the wake signal may be a high-to-low conversion on signal line  124  ( FIG. 1 ) while this signal line or bus idles at nominally 1.8 V. Moreover, as shown in  FIG. 2 , wake circuit  224  may include a buffer or a logic gate that can detect a digital value representing the wake signal. (Therefore, wake circuit  224  may function as a General Purpose Input/Output pin.) This digital value may be subsequently conveyed to integrated circuit  112  ( FIG. 1 ). 
     Furthermore, temperature-monitoring circuit  216  may include a comparator  226  and an AND gate  228  (and, more generally, control logic) to detect the wake signal when the temperature state of battery pack  114  and/or battery  116  ( FIG. 1 ) is being monitored. (Thus, comparator  226  and AND gate  228  may constitute a wake circuit.) In particular, when the temperature state is being monitored, the wake signal from battery-monitoring mechanism  120  may include pulling the voltage on signal line  124  ( FIG. 1 ) below a minimum voltage level associated with temperature sensor  122  in  FIG. 1  (such as a voltage below 0.1 V). This low-voltage wake signal may be detected by comparator  226 . If multiplexer  218  is currently selectively coupling temperature-monitoring circuit  216  and battery pack  114  ( FIG. 1 ), as indicated by the control signal, AND gate  228  may output a digital value indicating that the wake signal is present. This digital value may be conveyed to integrated circuit  112  ( FIG. 1 ). 
     Operation of power-management unit  110  is further illustrated in  FIGS. 3 and 4 .  FIG. 3  presents a block diagram illustrating operation of power-management unit  110  during a so-called ‘gas-gauge mode,’ in which multiplexer  218  selectively couples signal line  128  to signal line  124  (i.e., integrated circuit  112  communicates data with battery-monitoring mechanism  120 ), as shown by the bold line in  FIG. 3 . When signal line  128  is selectively coupled to signal line  124 , a nominal voltage on signal line  124  may be pulled up to a supply voltage (such as 1.8 V). 
     As noted previously, during a subsequent ‘temperature-monitoring mode,’ multiplexer  218  may selectively couple temperature-monitoring circuit  216  and signal line  124  based on the control signal. Alternatively, multiplexer  218  may revert to a default condition (and, thus, the temperature-monitoring mode) a time interval after selectively coupling signal line  128  to signal line  124 . As described further below with reference to  FIG. 5 , because of either of these mechanisms, a time duration of the gas-gauge mode may be 500 ms. More generally, the time duration may be a fraction of a thermal time constant of battery pack  114  and/or battery  116 , so that the temperature state does not change appreciably during the time duration. 
       FIG. 4  presents a block diagram illustrating operation of power-management unit  110  during the temperature-monitoring mode. As noted previously, temperature-monitoring circuit  216  may periodically monitor the temperature state of battery pack  114  and/or battery  116 , as shown by the bold line in  FIG. 4 . For example, as described further below with reference to  FIG. 5 , during the temperature-monitoring mode, temperature-monitoring circuit  216  may monitor the temperature state for 200 μs every 10 ms. Once again, this duty cycle and monitoring period may be selected based on a thermal time constant of battery pack  114  and/or battery  116 , so that the temperature state does not change appreciably between determinations of the temperature state by temperature-monitoring circuit  216 . 
     Note that transitioning from the temperature-monitoring mode to the gas-gauge mode may be initiated by integrated circuit  112  via interface circuit  214 . If the host is in a power-saving or sleep mode, battery-monitoring mechanism  120  may first wake up the host by conveying the wake signal via signal line  124 . After integrated circuit  112  is in the normal operating mode, it may instruct power-management unit  110  (and, thus, multiplexer  218 ) to transition to the gas-gauge mode. 
       FIG. 5  presents a timing diagram  500  illustrating operation of power-management unit  110 . During temperature-monitoring mode  510 , control signal  512  may facilitate selective coupling by multiplexer  218  of temperature-monitoring circuit  216  and temperature sensor  122  ( FIGS. 1-4 ) for 200 μs every 10 ms. During the temperature monitoring, signal  514  on signal line  124  ( FIGS. 1 and 3-4 ) may vary between approximately 0.1 and 2.5 V (depending on the temperature of battery pack  114  and/or battery  116  in  FIGS. 1 and 3-4 ). Similarly, during gas-gauge mode  516 , control signal  512  may facilitate selective coupling by multiplexer  218  of integrated circuit  112  and battery-monitoring mechanism  120  ( FIGS. 1 and 3-4 ) for approximately 500 ms, so that data  518  can be transferred using a single-wire communication protocol. 
     We now describe embodiments of a method.  FIG. 6  presents a flowchart illustrating a method  600  for conveying a signal that represents a temperature state of a battery pack (or a battery) and communicating data between an integrated circuit and the battery pack on a signal line, which may be performed by a power-management unit (such as power-management unit  110  in  FIG. 1 ). Based on a control signal, the power-management unit selectively couples the signal line to the integrated circuit that communicates with a battery-monitoring mechanism in the battery pack (operation  610 ). Subsequently, based on the control signal, the power-management unit selectively couples the signal line to a temperature-monitoring circuit that determines the temperature state of the battery pack (operation  612 ). 
     In some embodiments of method  600 , there may be additional or fewer operations. Moreover, the order of the operations may be changed, and/or two or more operations may be combined into a single operation. 
     Referring back to  FIG. 1 , in general functions of the power management unit  110  may be implemented in hardware to ensure safe and reliable operation even in the face of software and/or component failures. However, in some embodiments at least some of the operations performed in electronic device  100  are implemented in software. Thus, electronic device  100  may include one or more program modules or sets of instructions stored in an optional memory subsystem  134  (such as DRAM or another type of volatile or non-volatile computer-readable memory), which may be executed by a processing subsystem in integrated circuit  112 . (In general, the power-management technique may be implemented more in hardware and less in software, or less in hardware and more in software, as is known in the art.) Note that the one or more computer programs may constitute a computer-program mechanism. Furthermore, instructions in the various modules in optional memory subsystem  134  may be implemented in: a high-level procedural language, an object-oriented programming language, and/or in an assembly or machine language. Note that the programming language may be compiled or interpreted, e.g., configurable or configured, to be executed by the processing subsystem. 
     Components in electronic device  100  may be coupled by signal lines, links or buses. While electrical communication has been used as an illustrative example, in general these connections may include electrical, optical, or electro-optical communication of signals and/or data. Furthermore, in the preceding embodiments, some components are shown directly connected to one another, while others are shown connected via intermediate components. In each instance the method of interconnection, or ‘coupling,’ establishes some desired communication between two or more circuit nodes, or terminals. Such coupling may often be accomplished using a number of circuit configurations, as will be understood by those of skill in the art; for example, AC coupling and/or DC coupling may be used. 
     In some embodiments, functionality in these circuits, components and devices may be implemented in one or more: application-specific integrated circuits (ASICs), field-programmable gate arrays (FPGAs), and/or digital signal processors (DSPs). Furthermore, the circuits and components may be implemented using bipolar, PMOS and/or NMOS gates or transistors, and signals in these embodiments may include digital signals that have approximately discrete values and/or analog signals that have continuous values. Additionally, components and circuits may be single-ended or differential, and power supplies may be unipolar or bipolar. 
     Furthermore, charger  130  may include any combination of hardware and/or software implemented using analog and/or digital circuitry, and may include one or more processors, and volatile and nonvolatile memory. In some embodiments, charger  130  includes more than one chip or chip set, and in other embodiments charger  130  may operate in conjunction with a system management controller (SMC) in integrated circuit  112  that performs some of the functions of charger  130 . In these embodiments, the charger and SMC may operate in a master-slave or slave-master configuration. 
     Additionally, battery pack  114  can be any type of battery pack capable of powering electronic device  100 , and can be implemented in any technology. In some embodiments, battery pack  114  includes more than one separate battery and/or battery cell. 
     An output of a process for designing an integrated circuit, or a portion of an integrated circuit, comprising one or more of the circuits described herein may be a computer-readable medium such as, for example, a magnetic tape or an optical or magnetic disk. The computer-readable medium may be encoded with data structures or other information describing circuitry that may be physically instantiated as an integrated circuit or portion of an integrated circuit. Although various formats may be used for such encoding, these data structures are commonly written in: Caltech Intermediate Format (CIF), Calma GDS II Stream Format (GDSII) or Electronic Design Interchange Format (EDIF). Those of skill in the art of integrated circuit design can develop such data structures from schematics of the type detailed above and the corresponding descriptions and encode the data structures on a computer-readable medium. Those of skill in the art of integrated circuit fabrication can use such encoded data to fabricate integrated circuits comprising one or more of the circuits described herein. 
     Electronic device  100  may include a variety of devices that can include a battery pack, and that can receive electrical current from an adapter and a charger, including: a laptop computer, a media player (such as an MP3 player), an appliance, a subnotebook/netbook, a tablet computer, a smartphone, a cellular telephone, a network appliance, a set-top box, a personal digital assistant (PDA), a toy, a controller, a digital signal processor, a game console, a device controller, a computational engine within an appliance, a consumer-electronic device, a portable computing device or a portable electronic device, a personal organizer, and/or another electronic device. 
     Although we use specific components to describe electronic device  100 , in alternative embodiments, different components and/or subsystems may be present in electronic device  100 . For example, battery  114  may include a protective circuit to prevent battery  116  from being damaged during operation. Additionally, one or more of the components may not be present in electronic device  100 . Moreover, in some embodiments, electronic device  100  may include one or more additional components that are not shown in  FIG. 1 . Also, although separate components are shown in  FIG. 1 , in some embodiments, some or all of a given component can be integrated into one or more of the other components in electronic device  100  and/or positions of components in electronic device  100  can be changed. 
     In the preceding description, we refer to ‘some embodiments.’ Note that ‘some embodiments’ describes a subset of all of the possible embodiments, but does not always specify the same subset of the embodiments. 
     The foregoing description is intended to enable any person skilled in the art to make and use the disclosure, and is provided in the context of a particular application and its requirements. Moreover, the foregoing descriptions of embodiments of the present disclosure have been presented for purposes of illustration and description only. They are not intended to be exhaustive or to limit the present disclosure to the forms disclosed. Accordingly, many modifications and variations will be apparent to practitioners skilled in the art, and the general principles defined herein may be applied to other embodiments and applications without departing from the spirit and scope of the present disclosure. Additionally, the discussion of the preceding embodiments is not intended to limit the present disclosure. Thus, the present disclosure is not intended to be limited to the embodiments shown, but is to be accorded the widest scope consistent with the principles and features disclosed herein.

Metadata:
Filing Date: 20121224
Publication Date: 20171024
Grant Date: 20171024
Priority Date: 20120307
Inventors: PATEL PARIN
MULLINS SCOTT P.
Assignee: APPLE INC
CPC Classifications: [{"code": "H01M10/486", "inventive": true, "first": false, "tree": "[]"}, {"code": "G06F1/32", "inventive": true, "first": false, "tree": "[]"}, {"code": "G01K13/00", "inventive": true, "first": true, "tree": "[]"}, {"code": "H01M10/486", "inventive": true, "first": false, "tree": "[]"}, {"code": "A61K31/56", "inventive": true, "first": false, "tree": "[]"}, {"code": "H01M10/443", "inventive": true, "first": false, "tree": "[]"}, {"code": "H01M10/425", "inventive": true, "first": false, "tree": "[]"}, {"code": "G01N2500/00", "inventive": false, "first": false, "tree": "[]"}, {"code": "H01M2010/4278", "inventive": false, "first": false, "tree": "[]"}, {"code": "G06F1/3206", "inventive": true, "first": false, "tree": "[]"}, {"code": "G01N33/5041", "inventive": true, "first": false, "tree": "[]"}, {"code": "G06F1/206", "inventive": true, "first": false, "tree": "[]"}, {"code": "Y02B60/1275", "inventive": false, "first": false, "tree": "[]"}, {"code": "H01M2010/4271", "inventive": false, "first": false, "tree": "[]"}, {"code": "H01M10/486", "inventive": true, "first": false, "tree": "[]"}, {"code": "G06F1/3206", "inventive": true, "first": true, "tree": "[]"}, {"code": "H01M2010/4278", "inventive": false, "first": false, "tree": "[]"}, {"code": "H01M10/486", "inventive": true, "first": false, "tree": "[]"}, {"code": "H01M10/443", "inventive": true, "first": false, "tree": "[]"}, {"code": "H01M10/425", "inventive": true, "first": false, "tree": "[]"}, {"code": "Y02D10/00", "inventive": false, "first": false, "tree": "[]"}, {"code": "Y02E60/10", "inventive": false, "first": false, "tree": "[]"}, {"code": "G06F1/206", "inventive": true, "first": true, "tree": "[]"}, {"code": "G01K13/00", "inventive": true, "first": true, "tree": "[]"}, {"code": "G06F1/3206", "inventive": true, "first": false, "tree": "[]"}, {"code": "H01M2010/4278", "inventive": false, "first": false, "tree": "[]"}, {"code": "G06F1/206", "inventive": true, "first": false, "tree": "[]"}, {"code": "H01M10/425", "inventive": true, "first": false, "tree": "[]"}, {"code": "G01N33/5041", "inventive": true, "first": false, "tree": "[]"}, {"code": "G06F1/32", "inventive": true, "first": false, "tree": "[]"}, {"code": "A61K31/56", "inventive": true, "first": false, "tree": "[]"}, {"code": "G01N2500/00", "inventive": false, "first": false, "tree": "[]"}, {"code": "Y02D10/00", "inventive": false, "first": false, "tree": "[]"}, {"code": "Y02D10/00", "inventive": false, "first": false, "tree": "[]"}, {"code": "H01M2010/4271", "inventive": false, "first": false, "tree": "[]"}, {"code": "G06F1/3206", "inventive": true, "first": false, "tree": "[]"}, {"code": "H01M10/443", "inventive": true, "first": false, "tree": "[]"}, {"code": "G06F1/32", "inventive": true, "first": false, "tree": "[]"}, {"code": "H01M10/425", "inventive": true, "first": false, "tree": "[]"}, {"code": "H01M10/443", "inventive": true, "first": false, "tree": "[]"}]
Family ID: 49117289