Abstract:
Apparatus includes a first connection to a battery; a second connection to a component; a first path between the first and second connections including a non-upconverting voltage regulator and being absent of a voltage upconverter; a second path between the first and second connections including a voltage upconverter; and a controller. The controller is configured to determine a minimum operating voltage of the component; to determine whether a voltage provided at the first connection meets a predetermined relationship with respect to the minimum operating voltage of the component; and on a positive determination, to enable the first path and disable the second path, and on a negative determination, to disable the first path and enable the second path.

Description:
FIELD OF THE INVENTION 
       [0001]    This invention relates to a method comprising providing power from a battery to a component. The invention relates also to apparatus comprising connecting a connection to a battery to a connection to a component. The invention relates also to software. 
       BACKGROUND 
       [0002]    In order to connect a portable communications device, such as a mobile phone or laptop computer, to a cellular telephony network operating according to for example the GSM and UMTS standards, it is necessary for the device to include a subscriber identity module (SIM) card. SIM cards currently are implemented by universal integrated circuit cards (UICCs). SIM cards are standardised both in size and in the protocols that are used to transfer data to and from the SIM card. A UICC typically includes a CPU (central processing unit), ROM (read only memory), RAM (random access memory), EEPROM (electrically erasable programmable read only memory) and I/O (input/output) circuits. A UICC card will typically include storage of a few hundred kilobytes. 
         [0003]    Originally, SIM cards required a supply voltage of 5 volts, although more commonly now the required supply voltage is 3 volts. Some SIM cards require a lower voltage of 1.8 volts. 
         [0004]    Battery technology prevalent in mobile communication devices is Carbon-Lithium Cobalt Oxide (C—LiCoO2) battery technology. Batteries constructed using this technology have a discharge cut-off of around 3.1 volts. Since a SIM card needs to be operational in order for a mobile device to be able to communicate via a mobile telephone network, SIM cards are provided with battery power via a voltage upconverter, for instance a buck/boost converter. 
       SUMMARY 
       [0005]    A first aspect of the invention provides a method comprising:
       determining a battery voltage;   determining a minimum operating voltage of a component;   determining whether the battery voltage meets a predetermined relationship with respect to the minimum operating voltage of the component; and
           on a positive determination, causing a connection from a battery to the component via a non-upconverting voltage regulator and absent of a voltage upconverter, and   on a negative determination, causing a connection from the battery to the component via a voltage up converter.   
               
 
         [0011]    The non-upconverting voltage regulator may be a low dropout regulator (LDO). 
         [0012]    The voltage upconverter may be part of a buck/boost converter. On a positive determination, the method of the embodiments comprises causing a connection from the battery to the component via a non-upconverting voltage regulator and absent of a buck/boost converter. 
         [0013]    The invention also provides a computer program, optionally stored on a medium, comprising machine readable instructions that when executed by computing apparatus control it to perform the method of any preceding claim. Other embodiments are hardware implementations and others are software/hardware implementations. 
         [0014]    A second aspect of the invention provides apparatus comprising:
       a first connection to a battery;   a second connection to a component;   a first path between the first and second connections including a non-upconverting voltage regulator and being absent of a voltage upconverter;   a second path between the first and second connections including a voltage upconverter; and   a controller configured:
           to determine a minimum operating voltage of the component;   to determine whether a voltage provided at the first connection meets a predetermined relationship with respect to the minimum operating voltage of the component; and   on a positive determination, to enable the first path and disable the second path, and   on a negative determination, to disable the first path and enable the second path.   
               
 
         [0024]    A third aspect of the invention provides apparatus comprising:
       a first connection to a battery;   a second connection to a component;   means for determining a minimum operating voltage of the component;   means responsive to a determination that a voltage provided at the first connection meets a predetermined relationship with respect to the minimum operating voltage of the component to connect the first and second connections by a path including a non-upconverting voltage regulator and absent of a voltage upconverter; and   means responsive to a determination that the voltage provided at the first connection does not meet the predetermined relationship with respect to the minimum operating voltage of the component to connect the first and second connections by a second path including a voltage upconverter.       
 
         [0030]    A fourth aspect of the invention provides a module configured:
       to determine a minimum operating voltage of a component;   to determine whether a battery voltage meets a predetermined relationship with respect to the minimum operating voltage of the component; and
           on a positive determination, to cause the battery voltage to be provided to the component by a first path including a non-upconverting voltage regulator and absent of a voltage upconverter, and   on a negative determination, to cause the battery voltage to be provided to the component by a second path including a voltage upconverter. wherein the controller is configured to determine whether the battery voltage meets a predetermined relationship with respect to the minimum operating voltage of the component by determining whether the battery voltage exceeds a threshold that is greater than the minimum operating voltage of the component.   
               
 
         [0035]    A fifth aspect of the invention provides apparatus, comprising:
       at least one processor; and   at least one memory including computer program code; the at least one memory and the computer program code configured to, with the at least one processor, cause the apparatus at least to perform:   determining whether a battery voltage meets a predetermined relationship with respect to a minimum operating voltage of a component; and
           on a positive determination, causing a connection from a battery to the component via a non-upconverting voltage regulator and absent of a voltage upconverter, and   on a negative determination, causing a connection from the battery to the component via a voltage up converter.   
               
 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0041]    Embodiments of the invention will now be described, by way of example only, with reference to accompanying drawings, in which: 
           [0042]      FIG. 1  is a schematic diagram of components forming part of a portable communications device embodying aspects of the invention; and 
           [0043]      FIG. 2  is a flowchart illustrating operation of the  FIG. 1  device according to certain aspects of the invention. 
       
    
    
     DETAILED DESCRIPTION OF THE EMBODIMENTS 
       [0044]      FIG. 1  illustrates a mobile device  10  embodying aspects of the invention. The mobile device  10  is shown as a mobile telephone, particularly a smart phone or personal digital assistant (PDA). Alternatively, the mobile device  10  may be a laptop computer, a tablet computer or other device. The device includes numerous components which are omitted from the figure and the following description for the sake of conciseness and clarity. 
         [0045]    Shown in  FIG. 1  are key components of the device  10  including a controller  11 , a buck/boost converter  12  and a SIM low drop-out regulator (LDO)  13 . The device  10  includes a battery connection  14  that comprises a positive terminal  15  and a negative or ground terminal  16 . A battery  17  is connected across the positive and negative terminals  15 ,  16 . The battery  17  may be integrated fully with the device  10  or it may be removable and replaceable by a user or by a service engineer. 
         [0046]    The mobile device  10  includes a connector  18  to a SIM card  19 . The SIM connector  18  includes at least one data terminal  20  and at least one power terminal  21 . In practice, plural terminals  21  are used to connect power between the device  10  and the SIM  19 , and plural terminals  20  are used to transfer data between the device  10  and the SIM  19 . 
         [0047]    The device  10  also includes a voltage detection module  22 , a switch  23  and first and second other LDOs  24 ,  25 . 
         [0048]    The voltage detector module  22  is connected across the positive and negative terminals  15 ,  16  of the battery connection  14 . The voltage detector module is arranged to detect a voltage VBat that is provided by the battery  17 . It will be appreciated that VBat at any given instant is dependent on a number of factors including the chemistry of the battery  17 , the charge level of the battery, the instantaneous load and the battery temperature. The battery voltage VBat is provided as an input to the buck/boost converter  12  and to the switch  23 . 
         [0049]    As is conventional, the buck/boost converter  12  includes a buck (step-down) converter followed by a boost (step-up) converter. The buck/boost converter  12  is configured and controlled such as to provide a voltage VBoost that is suitable for powering relevant components of the device  10  whenever there is sufficient charge remaining in the battery  17  to power the device. At low values of VBat, the buck/boost converter  12  operates to upscale the battery voltage VBat and provide a voltage VBoost at an output. Here, the buck/boost converter  12  operates in boost mode and VBoost is greater than VBat. However, at relatively high values of VBat, the buck/boost converter  12  operates in buck mode and VBoost is less than VBat. The buck/boost converter  12  can be described as a voltage upconverter for two reasons: firstly because it is operable to upconvert a received Voltage, although it may not upconvert at all times, and secondly because it includes a voltage upconverter. 
         [0050]    Components (not shown) of the device  10  are provided with a voltage supply that is derived from VBoost by the first and second other LDOs  24 ,  25 . 
         [0051]    The switch  23  also is provided with VBoost at a second input. As such, the switch  23  receives VBat at a first input and VBoost at the second input. An output of the switch  23  is provided to an input of the SIM LDO  13 . The power terminal  21  of the SIM connector  18  is connected to an output of the SIM LDO  13 . As will be explained below, the connection of the SIM LDO  13  to the SIM  19  provides the SIM  19  with electrical power. 
         [0052]    The data terminal  20  of the SIM connector  18  is connected to the controller  11 . This allows the controller  11  to communicate with the SIM  19 . 
         [0053]    The controller  11  may take any suitable form. For instance, the controller  11  may comprise control logic, for instance in the form of hardware gates. Alternatively, the controller  11  may be, for example, programmable hardware with embedded firmware. For instance, the controller  11  may comprise a microprocessor arrangement, as shown in  FIG. 1 . Here, the controller  11  comprises a processor  30  that is connected to a memory  31  and to input/outputs  32 . The memory is provided with one or more computer programs  33 . The one or more programs  33  include instructions that when executed by the process control it to perform a method of controlling the switch  23 , and thus controlling operation of the device  10 , based on decisions made using information received from the voltage detecting module  22  and the SIM  19 . This is explained in more detail below, particularly with reference to  FIG. 2 . The computer program instructions  33  may arrive at the controller  11  via an electromagnetic carrier signal or be copied from a physical entity such as a computer program product or memory device  34  or a record medium such as a CD-ROM or DVD  35 . 
         [0054]      FIG. 2  is a flowchart illustrating operation of the device, particularly the controller  11 . 
         [0055]    The operation of  FIG. 2  starts at step S 1  when the device  10  is powered up. At step S 2 , the type of the SIM  19  is detected. This is achieved by the controller  11  sending a request for information about the SIM type to the SIM  19  via the data connector  20  of the SIM connector  18 . The SIM  19  responds to the request with information from which the controller  11  can determine the type of SIM. The SIM type may be represented as a minimum operating voltage of the SIM  19  or in any other suitable manner from which the controller  11  can determine the minimum operating voltage of the SIM. For instance, the information from which the controller  11  can determine the type of SIM may be information identifying a class of device, or a model number. 
         [0056]    At step S 3 , the controller  11  determines whether the SIM  19  is a 1.8 volt SIM. Put generically, step S 3  involves the controller  11  determining whether the SIM  19  is of a predetermined type. On a positive determination, the operation proceeds to step S 4 . Here, the controller connects the battery  17  directly to the SIM LDO  13 . This is achieved by the controller  11  controlling the switch  23  to connect VBat to the SIM LDO  13  and to isolate VBoost from the SIM LDO. After step S 4 , the operation ends at step S 5 . 
         [0057]    In the event of a negative determination from step S 3 , operation proceeds to step S 6 . Here, VBat is compared to a threshold voltage X. The threshold voltage X is predetermined and stored in the controller  11 , for instance in the memory  31 . In these example embodiments, the threshold voltage X is equal to 3 volts plus an amount that is equal to or slightly greater than the operational voltage drop across the SIM LDO  13 . If VBat is greater than threshold voltage X, it can be assumed that VBat is sufficiently high to result in a voltage being provided to the SIM  19  that is sufficient to power the SIM  19 . If the threshold voltage X is not exceeded by VBat, it can be assumed that the battery voltage VBat may not be sufficiently high to power the SIM  19 . In the event of a negative outcome from step S 6 , operation proceeds to step S 7 . Here, the controller causes the battery  17  to be connected to the SIM  19  via the buck/boost converter  12 . This occurs by the controller  11  controlling the switch  23  to disconnect VBat from the SIM LDO  13  and instead to connect VBoost to the SIM LDO. Since VBoost is higher than VBat, step S 7  results in the SIM  19  being provided with a voltage that is sufficient to power the SIM. After step S 7 , the operation ends at step S 8 . 
         [0058]    If step S 6  yields a positive result, the operation proceeds to step S 9 . Here, the controller connects the battery  17  directly to the SIM LDO  13  without incorporating the buck/boost converter  12 . This is achieved by the controller  11  controlling the switch  23  to connect VBat directly to the SIM LDO  13  and to isolate VBoost. Step S 9  is similar to step S 4  in this regard. After step S 9 , the operation proceeds again to the input of step S 6 . 
         [0059]    The controller  11 , the voltage detector  22 , the switch  23 , the SIM LDO  13  and the buck/boost converter  12  may be provided as part of a single integrated circuit (IC). This IC may be provided on a printed wire board (PWB) along with the battery connectors  14 . Alternatively, the battery connectors  14  may be provided on a PWB that is separate to a board or substrate on which the IC is mounted. The SIM connectors  20 ,  21  may be connected to the same PWB as the battery connectors  14 , or they may be provided on a separate PWB. 
         [0060]    Execution of the method shown by the flowchart of  FIG. 2  results in operation of the mobile device that is advantageous for a number of reasons. 
         [0061]    In the event of the SIM  19  being a 1.8 volt SIM  19 , the SIM is powered directly from the battery  17 , not utilising the buck/boost converter  12 . This mode of operation results also when it is determined that VBat is sufficiently high to provide the minimum voltage required of a 3 volt SIM  19 , after allowing for a voltage drop across the SIM LDO  13 . In this mode of operation, i.e. where the buck/boost converter  12  is excluded from the connection between the battery  17  and the SIM  19 , power consumption of the device  10  is reduced because inefficiencies resulting from using the buck/boost converter  12  to provide a voltage to the SIM are avoided. Although the buck/boost converter  12  may still be utilised to provide voltages to the other LDOs  24  and  25 , the power drawn by the buck/boost converter  12  is less and so overall operating efficiency is improved. If, however, VBat is not sufficient to power the SIM  19 , after taking account of the voltage drop across the SIM LDO  13 , the buck/boost converter  12  is utilised to ensure that a sufficiently high voltage is provided to the power input  21  of the SIM  19  and thus ensure operation of the SIM  19 . This allows the SIM  19  to be powered even with low levels of charge remaining in the battery. 
         [0062]    Features of the device  10  described above allow the buck/boost converter  12  to be omitted from the path between the battery  17  and the SIM for much of the voltage curve of a C—LiCoO2 battery. With such batteries, VBat is likely to fall bellow the threshold voltage X only for a relatively small portion of the end of the voltage curve, i.e. when there is relatively little charge remaining in the battery. As such, improved efficiency can result across almost all of the discharge period of the battery, although the buck/boost converter  12  is used for a time at the end of the period. 
         [0063]    Features of the invention described above provide performance advantages also with other battery types. For instance, a battery of the type having chemistry Carbon-Lithium Iron Phosphate (C—LiFePO4) have a voltage curve that has a maximum of approximately 3.6 volts and a discharge cut-off voltage of approximately 2.8 volts. With such a voltage curve, VBat is sufficient to power a 3 volt SIM  19  without utilising the buck/boost converter  12  for a significant proportion of the discharge period, although the proportion is less than it is for C—LiCoO2 batteries. 
         [0064]    In the event of a detection that the SIM  19  is a low voltage SIM, for instance a 1.8 volt SIM, the battery voltage VBat can be provided to power the SIM  19  without involving the buck/boost converter  12  as long as the voltage VBat is sufficient to power the device  10 . 
         [0065]    The above has been described with reference to 1.8 volt and 3 volt SIM cards. However, it will be appreciated that the invention is not limited to such. Other embodiments of the invention incorporate the ability to provide SIM cards with different minimum voltage requirements with electrical power. This applies particularly to SIM cards with minimum voltages having values that are not in common use at the time of writing this patent specification. 
         [0066]    Other embodiments of the invention utilise the features described above to provide electrical power to components other than SIM cards. In these embodiments, a minimum operating voltage of the component is detected in any suitable way, using software, hardware or a combination of software and hardware, and a voltage upconverter is utilised in the provision of electrical power to the component only if a voltage provided directly by a battery is not sufficient to meet the minimum voltage requirement of the component, taking into account voltage drops across any component(s) in the path between the battery and the component. In these other embodiments, the features described above provide electrical power to phone or laptop components or peripherals such as a display, memory, a camera, a CWS devices such as a Bluetooth module etc. 
         [0067]    It should be realized that the foregoing example embodiments should not be construed as limiting. Other variations and modifications will be apparent to persons skilled in the art upon reading the present application. 
         [0068]    Moreover, the disclosure of the present application should be understood to include any novel features or any novel combination of features either explicitly or implicitly disclosed herein or any generalization thereof and during the prosecution of the present application or of any application derived therefrom, new claims may be formulated to cover any such features and/or combination of such features.