PATENT DOCUMENT

Publication Number: US-11303138-B2
Application Number: US-201916443678-A
Country: US
Kind Code: B2

Title: Battery case power system

Abstract:
A battery case is operable with an electronic device such as a cellular telephone. The battery case has a battery that can be used to supply power to the electronic device. The battery case is configured to receive power from a power supply that is coupled to a mains power supply using a wired path or to receive power from a wireless charging mat or other wireless power transmitting device. Circuitry in the battery case may include direct-current-to-direct-current power converter circuitry, current sensor circuitry, switching circuitry, and other circuitry for controlling currents and voltages in the battery case and communicating with other electronic devices.

Claims:
What is claimed is: 
     
       1. A battery case that is operable in a system having a first electronic device that supplies power and a second electronic device that consumes power, comprising:
 a housing that removably attaches to the second electronic device; 
 a battery; 
 a power converter that is configured to receive an input voltage associated with the power supplied by the first electronic device and that is configured to step up the input voltage to supply a corresponding stepped-up output voltage, via an output, to the second electronic device without supplying power to the battery; and 
 a switch coupled between the power converter and the output, wherein the switch is in a first state when the stepped-up voltage is supplied to the second electronic device and is in a second state, different than the first state, when decoupling the power converter from the output. 
 
     
     
       2. The battery case of  claim 1 , wherein the switch is closed in the first state and is open in the second state, wherein the electronic device comprises a cellular telephone with a first connector, wherein the battery case comprises a second connector configured to mate with the first connector, and wherein the stepped-up output voltage is provided from the power converter to the second electronic device through the first and second connectors. 
     
     
       3. The battery case of  claim 2  wherein the first electronic device comprises a wireless power transmitter, wherein the battery case comprise a coil and a rectifier configured to receive wireless power from the wireless power transmitter, and wherein the rectifier supplies the input voltage to the power converter. 
     
     
       4. The battery case of  claim 2  wherein the first electronic device comprises a power supply configured to receive alternating-current mains power and wherein the battery case has a third connector that is configured to mate with a fourth connector in the power supply. 
     
     
       5. A battery case that is operable in a system having a first electronic device and a second electronic device, wherein the second electronic device is configured to draw a first amount of power in a first state and a second amount of power that is greater than the first amount of power in a second state, comprising:
 a housing that removably attaches to the second electronic device; 
 circuitry having an input and an output; 
 a battery, wherein the circuitry is configured to use the output to supply the first amount of power to the second electronic device from the first electronic device when the second electronic device is in the first state and wherein the circuitry is configured to use the output to supply the second amount of power to the second electronic device when the second electronic device is in the second state by supplying a portion of the second amount of power less than a threshold amount to the electronic device from the first electronic device and by supplying a difference between the threshold amount and the second amount of power from the battery; 
 a current sensor configured to monitor an amount of current flowing into the battery; and 
 a switch configured to control the amount of current flowing into the battery to prevent excessive charging currents. 
 
     
     
       6. The battery case of  claim 5  wherein the connector is configured to mate with a corresponding connector in the first electronic device. 
     
     
       7. The battery case of  claim 5  further comprising a coil that is configured to receive wireless power signals from the first electronic device. 
     
     
       8. A battery case that is operable with an electronic device, the battery case comprising:
 a housing that is removably coupled to the electronic device; 
 a first connector that is removably connected to a mating second connector in the electronic device; 
 power receiving circuitry; 
 a battery that produces a battery voltage; and 
 circuitry coupled between the battery and the first connector, wherein the circuitry is configured to provide power to the electronic device from the power receiving circuitry when the electronic device has a first power consumption, wherein the circuitry includes first and second switches coupled between the battery and the first connector, wherein the circuitry is configured to close the first and second switches to provide the battery voltage to the first connector when the electronic device has a second power consumption that is greater than the first power consumption, wherein an amount by which the second power consumption exceeds a predetermined threshold is supplied from the battery while the first and second switches are closed, and wherein the mating second connector receives the battery voltage from the first connector when the first and second connectors are connected. 
 
     
     
       9. The battery case of  claim 8  wherein the electronic device is a cellular telephone and wherein the housing is configured to receive the cellular telephone. 
     
     
       10. The battery case of  claim 9  wherein the battery has first and second battery cells coupled in series. 
     
     
       11. A battery case that is operable with an electronic device, comprising:
 a housing that is removably attached to the electronic device; 
 a battery; and 
 circuitry configured to:
 receive a sequence of power data objects; 
 reorder the received sequence of power data objects; and 
 provide the reordered sequence of power data objects to the electronic device. 
 
 
     
     
       12. The battery case of  claim 11  wherein the circuitry is configured to add a power data object associated with the battery to the received sequence of power data objects. 
     
     
       13. A battery case that is operable in a system having a first electronic device and a second electronic device, wherein the first electronic device is configured to supply power, the battery case comprising:
 a housing that removably attaches to the second electronic device; 
 circuitry having an input and an output and at least one signal line connected between the input and the output; and 
 a battery, wherein the circuitry is configured to:
 supply a sequence of power data objects from the first electronic device to the second electronic device over the signal line; 
 receive the sequence of power data objects from the second device; 
 reorder the received sequence of power data objects; and 
 provide the reordered sequence of power data objects to the second electronic device using the output. 
 
 
     
     
       14. The battery case of  claim 13  wherein the circuitry is further configured to add a power data object to the received sequence of power data objects before reordering the sequence of power data objects. 
     
     
       15. The battery case of  claim 14  wherein the added power data object characterizes a voltage and current available from the battery when supplying power to the second electronic device. 
     
     
       16. The battery case of  claim 13 , wherein the first electronic device has a first connector and the battery case has a second connector that mates with the first connector. 
     
     
       17. The battery case of  claim 16  wherein the first electronic device comprises a power adapter configured to receive mains power. 
     
     
       18. A battery case that is operable in a system having a first electronic device and a second electronic device, comprising:
 a housing that removably attaches to the second electronic device; 
 a battery; and 
 circuitry that is configured to:
 supply power to the second electronic device from the first electronic device; and 
 in response to determining that the second electronic device is drawing a current exceeding a threshold amount, supply power less than or equal to the threshold amount to the second electronic device from the first electronic device and supply power exceeding the threshold amount to the second electronic device from the battery without using a battery on the second electronic device to power operations on the second electronic device. 
 
 
     
     
       19. The battery case of  claim 18  wherein the first electronic device comprises a cellular telephone and wherein the housing is configured to removably receive the cellular telephone. 
     
     
       20. The battery case of  claim 19  wherein the cellular telephone is configured to draw the current exceeding a threshold current amount in response to activation of a voice-activated assistant on the cellular telephone and wherein the battery is at least partly used in supplying the current exceeding the threshold current amount.

Description:
This application claims the benefit of provisional patent application No. 62/780,827, filed Dec. 17, 2018, which is hereby incorporated by reference herein in its entirety. 
    
    
     FIELD 
     This relates generally to power systems, and, more particularly, to power systems with battery cases. 
     BACKGROUND 
     Electronic devices such as cellular telephones have batteries. The use of batteries allows cellular telephones to be portable. In some situations, the battery capacity of a cellular telephone battery may be supplemented using a removable battery case. When the removable battery case is not coupled to the cellular telephone, the cellular telephone can use the battery in the cellular telephone for power. When the removable case is coupled to the cellular telephone, power may be provided to the cellular telephone using the battery in the removable case and/or the cellular telephone battery. 
     If care is not taken, systems with battery cases may not handle power as efficiently as possible or may not satisfy a user&#39;s expectations during use. 
     SUMMARY 
     A battery case is operable with an electronic device such as a cellular telephone. The battery case has a battery that can be used to supply power to the electronic device. The battery case may receive power from a power supply using a wired connection or may receive power wirelessly from a wireless charging mat or other wireless power transmitting device. Circuitry in the battery case includes direct-current-to-direct-current power converter circuitry, current sensor circuitry, switching circuitry, and other circuitry for charging the battery in the battery case and otherwise controlling currents and voltages in the battery case. 
     The circuitry may be configured to step up an input voltage to ensure that the electronic device receives sufficient voltage from the case, may be configured to use the battery to maintain a desired level of power delivery from the case in the event that the case is plugged into a low capacity power supply during operation, may be configured to directly supply an elevated battery voltage from a set of series-connected battery cells to the electronic device, may be configured to reorder a sequence (e.g., a list) of power data objects, may be configured to receive power data objects from a power source via the electronic device, and may be configured to handle power spikes by selectively drawing on battery power during operation. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a schematic diagram of an illustrative wireless power system in accordance with an embodiment. 
         FIG. 2  is a circuit diagram of illustrative wireless power circuitry in accordance with an embodiment. 
         FIG. 3  is a schematic diagram of illustrative electronic device circuitry in accordance with an embodiment. 
         FIG. 4  is a circuit diagram of an illustrative wireless power system in accordance with an embodiment. 
         FIG. 5  is a diagram of illustrative operations involved in using a wireless power system in accordance with an embodiment. 
         FIG. 6  is a graph showing an illustrative current drawn by an electronic device in accordance with an embodiment. 
         FIG. 7  is a graph showing how battery power in a battery case can be used to supply peak current when the current drawn by an attached electronic device exceeds a threshold amount in accordance with an embodiment. 
     
    
    
     DETAILED DESCRIPTION 
     Electronic devices such as cellular telephones and battery cases contain batteries. Power sources such as wireless charging mats and wired power supplies are used in charging the batteries. An exploded side view of an illustrative system in which wired and wireless paths are used to convey power to devices such as a battery case and an associated electronic device is shown in  FIG. 1 . As shown in  FIG. 1 , system  8  includes electronic devices  10 . Each electronic device  10  includes control circuitry. The electronic devices may also have additional components such as input-output devices, batteries, wireless power circuitry, and/or other circuitry. 
     Devices  10  may be any suitable electronic devices such as power adapters, wristwatches, cellular telephones or other handheld devices, laptop computers, tablet computers, accessories such as earbuds, electronic pencils (e.g., a stylus), or computer mice, other portable electronic devices, and/or other electronic equipment. In an illustrative configuration, which is sometimes described herein as an example, system  8  has a first electronic device  10 A, a second electronic device  10 B, a third electronic device  10 C, and a fourth electronic device  10 D. Electronic device  10 A is a wireless power transmitting device such as a wireless charging mat. Device  10 A has a housing such as housing  22 A (e.g., a housing with a planar upper charging surface on which devices to be charged are placed). Electronic device  10 D is a wired power adapter (sometimes referred to as a power brick or wired power supply). Terminals  24  of housing  22 D are configured to couple with a wall outlet supplying mains power. An alternating-current (AC) to direct-current (DC) power adapter is housed within housing  22 D and converts AC power that is received at terminals  24  into DC power. Cable  26  supplies the DC power to connector  16 D. 
     Electronic device  10 C is a portable electronic device such as a cellular telephone and electronic device  10 B is a battery case. Device  10 B has a housing such as housing  22 B with a recess R and/or other structures configured to receive housing  22 C of device  10 C. In this way, a user may removably attach device  10 C to device so that devices  10 B and  10 C may be used together as a portable unit. Housing  22 C may have planar front and rear faces (as an example). The front face, which faces upwardly in the orientation of  FIG. 1 , has a display. The rear face of housing  22 C faces towards housing  22 B of device  10 B. Device  10 C has a wired connector such as connector  16 A that is configured to mate with corresponding connectors such as wired connector  16 B of device  10 B, so that device  10 B can provide wired power to device  10 C. Device  10 B includes connector  16 C, which is configured to mate with connector  16 D of device  10 D so that power can be provided from device  10 D to device  10 B. Device  10 B can receive wireless power from device  10 A. In scenarios in which device  10 B is not present, connectors  16 D and  16 A may be coupled to each other so that device  10 D can supply wired power to device  10 C. 
     To provide device  10 C with supplemental power while protecting device  10 C from damage due to stress-producing events such as drop events, device  10 B is installed on device  10 C (e.g., housing  22 C of device  10 C may be placed within corresponding recess R in housing  22 B of device  10 B to removably couple device  10 B to  10 C). In this position, devices  10 B and  10 C may be carried in the pocket of a user (as an example). Connectors  16 A and  16 B mate when device  10 C is coupled to device  10 B so that battery power can be provided from device  10 B to device  10 C over a wired path. 
     When it is desired to receive wireless power from device  10 A, device  10 B (and, if desired, device  10 C within recess R), may be placed on the charging surface of device  10 A. Device  10 A may have one or more wireless power coils such as wireless power coil  12 . Coils such as coil  12  are used for inductive wireless power transfer and may therefore sometimes be referred to as inductive power coils. When it is desired to transmit wireless power, an alternating current is applied to coil  12 , which generates a corresponding alternating-current electromagnetic field. Wireless power that is transmitted in this way is received by corresponding nearby wireless power coils. As shown in  FIG. 1 , for example, device  10 C may have a wireless power coil such as coil  20  that can receive wireless power directly from coil  12  in the absence of device  10 B. Device  10 B has wireless power coil  14  that can receive wireless power from coil  12  and has connector  16 C that can receive wired power from connector  16 D of device  10 D. 
     Electrical components such as battery  18  may be mounted in housing  22 B of device  10 B. Electrical components such as battery  28  may be mounted in housing  22 C of device  10 C. 
     The devices  10  of  FIG. 1  may transmit power and/or may receive power using wireless and/or wired paths. Illustrative wireless power circuitry of the type that may be used in devices  10  is shown in  FIG. 2 . The wireless power circuitry of  FIG. 2  includes wireless power transmitter TX and wireless power receiver circuitry RX. During operation, wireless power signals  44  are transmitted by circuitry TX and received by circuitry RX. In the embodiment of  FIG. 2 , wireless power is transferred from coil  36  to coil  82  in a single direction. If desired, additional transmitter and receiver circuitry may be provided to allow wireless power to be transferred bidirectionally (e.g., to allow a first transmitter circuit to transmit power from coil  36  to coil  82  for reception by a first receiver circuit and to also allow a second transmitter circuit to transmit power from coil  82  to coil  36  for reception by a second receiver circuit). The unidirectional power transmission circuitry of  FIG. 2  is illustrative. 
     As shown in  FIG. 2 , circuitry TX includes inverter circuitry  80 . Control circuitry supplies control signals to inverter circuitry  80 . Inverter circuitry  80  supplies corresponding alternating-current drive signals to coil  36 . Circuit components such as capacitor  70  may be coupled in series with coil  36  as shown in  FIG. 2 . When alternating-current current signals are supplied to coil  36 , corresponding alternating-current electromagnetic signals (wireless power signals  44 ) are transmitted to nearby coils such as illustrative coil  82  in receiver circuitry RX. This induces a corresponding alternating-current (AC) current signal in coil  82 . Capacitors such as capacitors  72  may be coupled in series with coil  82 . Rectifier  50  receives the AC current from coil  82  and produces corresponding direct-current power (e.g., direct-current voltage Vrect) at output terminals  76 . This power may be used to power a load. 
     In a bidirectional wireless power system, wireless power transmitting circuitry such as inverter  80  and wireless power receiving circuitry such as receiver  50  may be coupled to a common coil. This allows the same coil to be used in receive wireless power (when the wireless power receiving circuitry is active) and in transmitting wireless power (when the wireless power transmitting circuitry is active). 
       FIG. 3  is a schematic diagram showing illustrative circuitry that may be used in each device  10  in system  8 . The circuitry of  FIG. 3  need not all be used in a given device. For example, some of the circuitry of device  10  of  FIG. 3  may be used in device  10 A but not in devices  10 B and  10 C. Device  10 A may, as an example, be a wireless charging mat that is coupled by a cable to a mains power supply (e.g., a wall outlet). In this arrangement, device  10 A may use an alternating-current-to-direct-current power converter such as AC-DC converter  90  to convert alternating-current (AC) mains power to direct-current (DC) power for use by device  10 A, whereas circuitry such as AC-DC converter  90  may be omitted from devices  10 B and  10 C. In an embodiment, device  10 D is a wired power adapter and does not contain wireless power circuitry or a battery. In other embodiments, device  10 D may contain a battery and/or different sets of components may be selectively omitted from each of devices  10 . 
     One or more devices  10  in system  8  may include wireless power circuitry  96  such as wireless power transmitter circuitry TX and/or wireless power receiver circuitry RX. For example, device  10 A may contain only transmitter circuitry TX and no receiver circuitry RX. Device  10 C may contain only receiver circuitry RX for receiving power from device  10 A and/or from device  10 B or, if desired, may contain both receiver circuitry RX (for receiving power from device  10 A and/or device  10 B) and transmitter circuitry TX (for transmitting power to an electronic device  10  such as a pair of earbuds, an electronic stylus, or other electronic device and/or for transmitting power to device  10 B). Device  10 B may contain circuitry RX (e.g., to receive power from device  10 A to charge a battery in device  10 B and, if desired, to receive power from device  10 C) and may optionally contain circuitry TX (e.g., to transmit power from the battery in device  10 B to device  10 C when devices  10 B and  10 C are coupled together and device  10 C desires supplemental power from device  10 B and/or to transmit power from the battery in device  10 B to other electronic devices). Other configurations (e.g., configurations in which device  10 A includes wireless power receiver circuitry RX, etc.) may also be used, if desired. Wireless power transmitter circuitry TX and wireless power receiver circuitry RX contain coils, as described in connection with coils  36  and  82  of  FIG. 2 . 
     Device  10 A, device  10 B, device  10 C, and device  10 D include control circuitry as shown by control circuitry  104  of device  10  of  FIG. 3 . Control circuitry  104  is used to control the operation of devices  10 A,  10 B,  10 C, and  10 D. This control circuitry may include processing circuitry associated with microprocessors, power management units, baseband processors, digital signal processors, microcontrollers, and/or application-specific integrated circuits with processing circuits. The processing circuitry implements desired control and communications features in devices  10 A,  10 B,  10 C, and  10 D. For example, the processing circuitry may be used in selecting coils, determining power transmission levels, processing sensor data and other data, processing user input, handling negotiations between devices (e.g., to establish power transfer settings), sending and receiving in-band and out-of-band data, making measurements, and otherwise controlling the operation of system  8 . 
     Control circuitry in system  8  such as control circuitry  104  may be configured to perform operations in system  8  using hardware (e.g., dedicated hardware or circuitry), firmware and/or software. Software code for performing operations in system  8  is stored on non-transitory computer readable storage media (e.g., tangible computer readable storage media) in control circuitry  104 . The software code may sometimes be referred to as software, data, program instructions, instructions, or code. The non-transitory computer readable storage media may include non-volatile memory such as non-volatile random-access memory (NVRAM), one or more hard drives (e.g., magnetic drives or solid state drives), one or more removable flash drives or other removable media, or the like. Software stored on the non-transitory computer readable storage media may be executed on the processing circuitry of control circuitry  104 . The processing circuitry may include application-specific integrated circuits with processing circuitry, one or more microprocessors, a central processing unit (CPU) or other processing circuitry. 
     Electronic devices  10 A,  10 B,  10 C, and  10 D may include input-output circuitry as shown by input-output devices  94  of  FIG. 3 . Input-output devices  94  may include light-based devices (e.g., displays, status indicator lights formed from light-emitting diodes or other light emitters, ambient light sensors, image sensors, optical proximity sensors, three-dimensional image sensors formed from light emitters that project beams of light and corresponding image sensors that detect dots where the projected light beams strike objects, camera flash components, and/or other circuits that emit and/or detect light), radio-frequency circuitry (e.g., radio-frequency circuitry such as radar circuitry and/or other radio-frequency circuitry for detecting the location and movement of objects), acoustic components (e.g., microphones for gathering sound and speakers for emitting sound), haptic output devices for providing vibrations and other haptic output, touch sensors, buttons, force sensors, joysticks, knobs, temperature sensors, gas sensors, and/or other circuitry for detecting user input and for measuring environmental data. 
     Electronic devices  10 A,  10 B,  10 C, and  10 D may be any suitable electronic devices. For example, device  10 A may be a stand-alone wireless power adapter (e.g., a wireless charging mat that includes power adapter circuitry), may be a wireless charging mat that is coupled to a power adapter or other equipment by a cable, may be a portable device, may be equipment that has been incorporated into furniture, a vehicle, or other system, or may be other wireless power transfer equipment. Illustrative configurations in which device  10 A is a wireless power transmitting device such as a wireless charging mat are sometimes described herein as an example. Electronic device  10 D may be a wired power adapter (e.g., a power brick) that plugs into mains power or a wired power adapter that supplies power from a battery. Electronic device  10 B may be a supplemental battery pack. For example, device  10 B may be a battery case that includes a battery such as battery  92  to provide supplemental battery power to electronic devices such as device  10 C and/or other electronic devices. Illustrative configurations in which device  10 B is a battery case (sometimes referred to as a supplemental enclosure, removable case, or removable battery case) are sometimes described herein as an example. Electronic device  10 C may be a cellular telephone or other portable electronic device (e.g., a tablet computer, laptop computer, wristwatch device, headphones, earbuds, stylus, or other electronic device). Illustrative configurations in which device  10 C is a cellular telephone are sometimes described herein as an example. 
     Devices  10 A,  10 B,  10 C, and/or  10 D may include wireless communications circuitry such as communications circuitry  102  of device  10  of  FIG. 3 . The wireless communications circuitry may be used by devices  10 A,  10 B,  10 C, and/or  10 D to allow these devices (or a subset of these devices) to communicate wirelessly using in-band or out-of-band communications. Circuitry  102  may, for example, have wireless transceiver circuitry (e.g., a wireless transmitter) that wirelessly transmits out-of-band signals to an external device using an antenna. Circuitry  102  may also have wireless transceiver circuitry (e.g., a wireless receiver) that is used to wirelessly receive out-of-band signals from an external device using the antenna. 
     Wireless communications circuitry  102  can use one or more coils (e.g., coils in transmitter circuitry TX and/or receiver circuitry RX) to transmit and/or receive in-band signals. Any suitable modulation scheme may be used to support in-band communications between devices  10 . With one illustrative configuration, frequency-shift keying (FSK) is used to convey in-band data from a power transmitting circuit to a power receiving circuit (e.g., the frequency of wireless power signals may be modulated when power is being transmitted from the power transmitting circuit to the power receiving circuit) and amplitude-shift keying (ASK) is used to convey in-band data from a wireless power receiving circuit to a wireless power transmitting circuit. Power transfer may be continue between devices during these FSK and ASK transmissions. Other types of in-band communications may be used, if desired. 
     During wireless power transmission operations, control circuitry  104  drives inverter circuitry in transmitter circuitry TX to supply AC drive signals to one or more coils at a given power transmission frequency. The power transmission frequency may be, for example, a predetermined frequency of about 125 kHz, at least 80 kHz, at least 100 kHz, less than 500 kHz, less than 300 kHz, or other suitable wireless power frequency. In some configurations, the power transmission frequency may be negotiated in communications between devices. In other configurations, the power transmission frequency may be fixed. 
     During wireless power transfer operations with a wireless power transmitting device (e.g., one of devices  10  in system  8 ), while power transmitter circuitry TX is driving AC signals into one or more of coils to produce wireless signals  44  at the power transmission frequency, communications circuitry  102  uses FSK modulation to modulate the power transmission frequency of the driving AC signals and thereby modulate the frequency of signals  44 . In a wireless power receiving device (e.g., another of devices  10  in system  8 ), a coil is used to receive signals  44 . Power receiver circuitry RX uses the received signals on the coil and the rectifier circuitry in circuitry RX to produce DC power. At the same time, wireless transceiver circuitry in the receiving device uses FSK demodulation to extract the transmitted in-band data from signals  44 . This approach allows FSK data (e.g., FSK data packets) to be transmitted in-band between devices  10  with coils while power is simultaneously being wirelessly conveyed from between devices  10  using the coils. 
     The foregoing discussion of FSK and ASK technologies describes a data transmission mechanism between compatible power transmitters and receivers. It is desirable for power transmitter and receiver circuitry to be able to communicate information such as received power, frequency information, states of charge, so forth, to control wireless power transfer. However, the above-described technology need not involve the transmission of personally identifiable information using FSK or ASK in order to function. Out of an abundance of caution, it is noted that to the extent that implementations of this charging technology involves the use of personally identifiable information, implementers should follow privacy policies and practices that are generally recognized as meeting or exceeding industry or governmental requirements for maintaining the privacy of users. In particular, personally identifiable information data should be managed and handled so as to minimize risks of unintentional or unauthorized access or use, and the nature of authorized use should be clearly indicated to users. 
     If desired, control circuitry  104  of devices  10  (e.g., device  10  of  FIG. 3 ) may have external object measurement circuitry  100  (sometimes referred to as foreign object detection circuitry or external object detection circuitry) that detects external objects on a charging surface or other wireless power output region associated with device  10 . Circuitry  100  can detect foreign objects such as coils, paper clips, and other metallic objects and can detect the presence of a wireless power receiving device in the vicinity of wireless power transmitting circuitry. During object detection and characterization operations, external object measurement circuitry  100  can be used to make measurements on coils in device  10  to determine whether any external electronic devices are present on or near device  10  (e.g., touching a surface of the housing of device  10 ). 
     In an illustrative arrangement, measurement circuitry  100  of control circuitry  104  contains signal generator circuitry (e.g., oscillator circuitry for generating AC probe signals at one or more probe frequencies, a pulse generator, etc.) and signal detection circuitry (e.g., filters, analog-to-digital converters, impulse response measurement circuits, etc.). The characteristics of the coil that receives a signal from measurement circuitry  100  depend on whether any foreign objects overlap that coil (e.g., coins, wireless power receiving devices, etc.) and also depend on whether a wireless power receiving device with a coil is present, which could increase the measured inductance of a coil. Signal measurement circuitry  100  is configured to apply signals to the coil and measure corresponding signal responses. For example, signal measurement circuitry  100  may apply an alternating-current probe signal while monitoring a resulting signal at a node coupled to the coil. As another example, signal measurement circuitry  100  may apply a pulse to the coil and measure a resulting impulse response (e.g., to measure coil inductance). Using measurements from measurement circuitry  100 , device  10  can determine whether an external object is present on the coil(s) of device  10 . 
     If desired, measurement circuitry  100  and/or other circuitry in device  10  of  FIG. 3  may be omitted from one or more of devices  10  to help reduce the cost and complexity of that device. For example, device  10 A may have a battery to help store energy or battery  92  may be omitted from device  10 A to reduce cost (e.g., in an embodiment in which device  10 A has AC-DC power converter  90  to receive mains power). Converter  90  may, if desired, be omitted from devices  10 B and  10 C to conserve space and reduce cost and complexity for those devices. In an embodiment, measurement circuitry  100  is included in device  10 A and is omitted from devices  10 B,  10 C, and  10 D. In an embodiment in which device  10 C has wireless power transmitter circuitry TX, device  10 C may include measurement circuitry  100 . In an embodiment in which device  10 C does not include wireless power transmitter circuitry TX, device  10 C need not include measurement circuitry  100  (as an example). 
     Communications circuitry  102  may likewise be incorporated and/or omitted from one or more of devices  10 . In some embodiments, a given one of devices  10  includes only transmitter circuitry TX or only receiver circuitry RX. If desired, one or more of devices  10 A,  10 B, and/or  10 C may include transmitter circuitry TX and receiver circuitry RX. 
       FIG. 4  is a circuit diagram showing how devices  10 A,  10 B,  10 C, and  10 D may be used together in system  8 .  FIG. 4  shows how devices  10 A and  10 B may be electromagnetically coupled (e.g., coil  120  of device  10 A may be electromagnetically coupled with coil  122  of device  10 B). This allows wireless power to be supplied to device  10 B from device  10 A. The wireless power signals that are received with coil  122  are rectified by rectifier  50 B and provided as direct-current (DC) power at node  100 . If desired, devices  10 D and  10 B may be coupled using a wired path (e.g., using connectors  16 D and  16 C). In this type of scenario, wired power (e.g., DC power from an AC-DC converter in device  10 D) is supplied to node  100  via path  103 . 
     Device  10 B includes circuitry such as switches, power converter circuitry, battery charging circuits, processing circuitry, connectors, current sensors, and/or other circuitry for operating device  10 B and system  8 . The circuit arrangement shown in the diagram of  FIG. 4  is illustrative. 
     As shown in the illustrative configuration of  FIG. 4 , control circuitry  104 B can close a switch such as switch  130  when it is desired to route voltage Vin at node  100  to regulator  132 . Regulator  132  is a direct-current-to-direct-current (DC-to-DC) power converter that converts the input voltage received via switch  130  to a desired output voltage on node  138  by circuitry in device  10 C. The voltage on node  138  and/or other power supply voltages in device  10 B may be used to power the circuitry of device  10 B. Control circuitry  104 B can close switch  134  when it is desired to route power (e.g., output voltage Vout) from regulator  132  to node  136 . Control circuitry  104 B can close switch  140  when it is desired to route power from battery  18  to device  10 C. 
     Device  10 C of  FIG. 4  is coupled via a wired connection to device  10 B using connector  16 B of device  10 B and mating connector  16 A of device  10 C. Device  10 C uses power from node  136  in powering the circuitry of device  10 C (e.g., to operate control circuitry, to operate communications circuitry, to operate components such as a display, to charge the battery of device  10 C, etc.). 
     When it is desired to charge battery  18 , control circuitry  104 B closes switch  140  and charges battery  18  using charging circuitry  142 . Battery  18  may be a lithium battery or other suitable battery and may have any suitable number of cells in parallel and/or serial configurations. In an embodiment, battery  18  is a lithium battery with two cells in series (a  2   s  configuration). During charging, charging circuitry  142  supplies a charging voltage to battery  142  through switch  140  while current sensor  144  monitors charging current. Control circuitry  104 B can use switch  140  (e.g., a field-effect transistor) to control the amount of current flowing into battery  18  during charging, thereby preventing excessive charging currents. 
     When it is desired to power device  10 C from battery power, switch  148  may be closed. In some situations, voltages in device  10 B can be boosted using power regulator circuitry in device  10 B. For example, battery voltage can be increased using regulator  132  (e.g., while switch  148  is open and switch  134  is closed). Current sensor  146  may be used to detect the total current flowing to charging circuit  142  and around the bypass path (i.e., the total current). The amount of current flowing into battery  140  may be determined using current sensor  144 . 
     One or more signal lines (e.g., data lines  150 ) may be used in passing signals between connector  16 D of device  10 D and connector  16 A of device  10 C. These signal lines may include, for example, Universal Serial Bus data lines. The pattern of the data lines may be reconfigurable. For example, switch  152  can be configured to couple a data line from connector  16 DC to control circuitry  104 B or to connector  16 B. Using data lines  150  and wireless communications circuitry associated with coils  120  and  122  and/or other wireless communications circuitry in devices  10 , devices  10 D and  10 C can communicate directly or indirectly with each other and devices  10 A and  10 C may communicate directly or indirectly with each other. Devices  10 C and  10 B can also communicate directly or indirectly and devices  10 A and  10 B can communicate directly or indirectly. During negotiations to establish appropriate power transmission levels in system  8 , for example, devices  10 B and/or  10 C may communicate with each other and may communicate with devices  10 A and/or  10 D. 
     When device  10 A or device  10 D is available to provide power to devices  10 B and  10 C, it may be desirable to route power to device  10 C through device  10 B. By providing power to device  10 C in this way whenever power is available from device  10 A or device  10 D, the battery in device  10 C is not depleted. There is a potential for voltage drops during power delivery from node  100  to node  136  e.g., as a function of the resistance of the path between nodes  100  and  136  and the current supplied, which gives rise to the possibility that the voltage at node  136  might be lower than desired (e.g., lower than 5V, even when the voltage Vin at node  100  is 5V). Accordingly, device  10 B uses DC-DC power converter circuitry (e.g., converter circuitry associated with regulator  132  or a battery charging circuit, etc.) to step up voltage Vin to a higher voltage. As an example, if Vin at the input of regulator  132  is 5V, the output voltage Vout that is provided to node  136  at the output of regulator  132  can be 8V (e.g., 8V at 1.5 A rather than 5V at 2.4 A). This ensures that device  10 C will receive sufficient voltage to operate properly when being powered through connector  16 A. 
     To preserve battery charge in device  10 C, device  10 C attempts to run its load using voltage Vout on node  136 , even in the absence of input power to device  10 B from device  10 A or device  10 D. In this scenario, device  10 B uses battery  18  to supply a given amount of power to device  10 C. For example, device  10 B may use battery  18  to deliver an amount of power such as 5 W of power that is sufficient for powering the operation of device  10 C without using the battery of device  10 C. During this mode of operation, device  10 A or device  10 D may become available to supply power. For example, a user may plug device  10 B into device  10 D to receive power. The maximum power capability of device  10 D may be less than the given amount of power being delivered by battery  18 . For example, device  10 D may only be capable of delivering 2.5 W. To avoid creating an undesired sudden drop in the amount of power available to device  10 C at node  136  in response to plugging device  10 C into a device  10 A that has less power available than the current amount of power being delivered from battery  18  to device  10 C, device  10 B automatically shifts from a first mode in which all 5W of power is supplied to device  10 C from battery  18  to a second mode in which device  10 D supplies as much power as possible from device  10 D (2.5 W in this example) while device  10 B makes up for the shortfall in power (5 W-2.5 W in this example) from battery  18 . In this second mode of operation, device  10 C continues to receive 5 W of power from node  136 , because device  10 B has ensured that 2.5 W is supplied to node  136  to make up for the shortfall in power from device  10 D (or, in other scenarios, the shortfall in power from device  10 A). An advantage of this arrangement is that device  10 C will not suddenly revert to using its own internal battery to make up for lost power when the power delivery from device  10 A or device  10 D falls below the level that was being delivered alone by device  10 B before device  10 A or device  10 D was present. This helps preserve battery charge in device  10 C and allows system  8  to operate satisfactorily for the user of device  10 C. 
     Whenever possible, device  10 C will attempt to charge its internal battery using the power supplied to node  136  by device  10 B. When node  136  is being supplied with power from battery  18 , this power can be used in charging the battery in device  10 C. Battery charging in device  10 C may involve using a DC-DC power converter in device  10 C to adjust the voltage Vout that is received by device  10 C to a desired voltage to use internally to charge the battery in device  10 C. Battery  18  is a  2   s  lithium battery, so battery  18  can supply about 6-8.6V to node  136  directly when switch  148  is closed (without incurring losses passing through a power converter). Because this voltage is sufficient to charge the internal battery in device  10 C without being stepped up to a higher voltage, power losses due to power converter step-up operations in device  10 B are not incurred, thereby enhancing charging efficiency. 
     System  8  may support Universal Serial Bus Power Delivery (USB PD) contract negotiations. These power contract negotiations involve sending sequences (e.g., lists) of available power data objects (PDOs) between power supplies and other devices. 
       FIG. 5  is a flow chart of illustrative operations involved in using PDOs in system  8 . 
     During the operations of block  160 , electronic devices  10  may exchange power data objects (voltage-current pairs associated with supported power delivery conditions). As an example, during contract negotiations, device  10 D may supply the following PDOs: PDO1: 5V at 1 A, PDO2: 5V at 3 A, PDO3: 9V at 2.5 A, and PDO4: 15V at 2 A. These PDOs can be conveyed directly from device  10 D to device  10 C via data lines  150  (e.g., a data line that passes directly from a pin in connector  16 C to a pin in connector  16 B). When conveyed directly in this way, control circuitry  104 B need not be involved in relaying the PDOs from device  10 D to device  10 C. The PDOs that are provided from device  10 D to device  10 C represent the power delivery capabilities of device  10 D. 
     During the operations of block  162 , device  10 C (e.g., a cellular telephone) provides the PDOs that were received from device  10 D to device  10 B. Device  10 B (e.g., a cellular telephone case in this example) adds an additional PDO to the sequence (list) of PDOs received from device  10 D via device  10 C during the operations of block  164 . The additional PDO represents the power delivery capability of device  10 B using battery  18 . This additional PDO may be, for example, a fifth PDO such as PDO5: 5.5-8.6V at 0.8 A. 
     During the operations of block  164 , device  10 B reorders the sequence of PDOs. The PDOs may, for example, be reordered so that PDOs that are expected to be associated with more efficient system operation are placed at the beginning of the reordered PDO sequence (e.g., at the top of the reordered PDO list) and the PDOs that are expected to be associated with less efficient operation are placed at the end of the reordered PDO sequence (e.g., at the bottom of the reordered PDO list). Device  10 B may consider states of charge, device capabilities, and other factors in determining how to reorder the sequence. As an example, if the battery of device  10 C is fully charged, device  10 B may conserve system power by placing PDO1 at the beginning of the PDO sequence (e.g., at the top of the PDO list). If, as another example, battery  18  of device  10 B is depleted, device  10 B may delete the battery option (PDO5) from the sequence. 
     After reordering the PDOs (e.g., from most efficient to least efficient), device  10 B presents the reordered PDO sequence (e.g., the reordered PDO list) to device  10 C and device  10 C obtains and uses this PDO sequence in determining which PDO to use in receiving power from device  10 D (block  166 ). Power delivery then proceeds using the selected PDO. In making a selection from the PDO sequence, device  10 C can be configured to always select the first item in the sequence (e.g., the top entry in the list). In this way, device  10 B can indirectly select the PDO for device  10 C to use without requiring that device  10 C understand the topology of system  8 . 
     As shown in the graph of  FIG. 6 , the current Ip drawn by the load of device  10 C may be characterized by intermittent spikes. For example, a user of device  10 C may launch a voice-activated assistant or may initiate downloading of a large file over a wireless connection. Operations such as these may be associated with spikes in power consumption and corresponding current spikes. Because relatively small changes in regulated current in system  8  have the potential to lead to undesired large sags in voltage, it can be challenging to regulate power in system  8  in the presence of current spikes in device  10 C. To help accommodate currents spikes without causing undesired supply voltage fluctuations, device  10 B (e.g., control circuitry  104 B) automatically switches battery  18  into use in response to detecting an increase in the current drawn by device  10 C (e.g., a current above a threshold amount). In this way, battery  18  serves as a power buffer that can help device  10 B to satisfy spikes in power demand without creating voltage sag that might otherwise occur if a spike in drawn current were to exceed the capacity of a voltage regulator circuit that is supplying power. 
     Consider, as an example, the graph of  FIG. 7 . In the graph of  FIG. 7 , current Ic represents the total amount of current that is supplied by device  10 B to device  10 C, which exhibits a spike at time t due to a spike in the current drawn by device  10 C (e.g., due to a spike in activity associated with launching a voice-controlled assistant, etc.). The total current Ic is made up of a first part that is not associated with battery  18  and a second part that is associated with battery  18 . The first portion of current Ic, which is represented by current Io in the graph of  FIG. 7 , may be supplied by device  10 A and/or device  10 D and may, if desired, pass through a regulator such as regulator  132  or other power converter before being received by device  10 C via terminal  136 . The second portion of current Ic, which is represented by battery current portion Ib in  FIG. 7 , may be supplied by from battery  18  when a need for supplying current in excess of threshold current Ith is detected (e.g., using switches  140  and  148 ). By satisfying peak demands in current from battery  18 , spikes in current Ic can be prevented from creating undesired sags in supply voltage while using device  10 B (and device  10 A or  10 D) to supply power to device  10 C. 
     The foregoing is merely illustrative and various modifications can be made to the described embodiments. The foregoing embodiments may be implemented individually or in any combination.

Metadata:
Filing Date: 20190617
Publication Date: 20220412
Grant Date: 20220412
Priority Date: 20181217
Inventors: Ben-Yehoshua, Lior
Luc, Brian R.
Henshaw, Glenn D.
Vaughn, Michael B.
Assignee: APPLE INC
CPC Classifications: [{"code": "H04M1/72412", "inventive": false, "first": false, "tree": "[]"}, {"code": "H04M1/72409", "inventive": true, "first": false, "tree": "[]"}, {"code": "H02J7/00045", "inventive": true, "first": false, "tree": "[]"}, {"code": "H01M10/425", "inventive": true, "first": true, "tree": "[]"}, {"code": "H02J7/0044", "inventive": true, "first": false, "tree": "[]"}, {"code": "H01M50/204", "inventive": true, "first": false, "tree": "[]"}, {"code": "H01M50/204", "inventive": true, "first": false, "tree": "[]"}, {"code": "H01M50/204", "inventive": true, "first": false, "tree": "[]"}, {"code": "H02J7/00045", "inventive": true, "first": false, "tree": "[]"}, {"code": "H04M1/0262", "inventive": false, "first": false, "tree": "[]"}, {"code": "H02J7/0044", "inventive": true, "first": false, "tree": "[]"}, {"code": "H02J50/80", "inventive": true, "first": false, "tree": "[]"}, {"code": "H04M2250/74", "inventive": false, "first": false, "tree": "[]"}, {"code": "H02J7/0013", "inventive": true, "first": false, "tree": "[]"}, {"code": "H02J7/342", "inventive": true, "first": false, "tree": "[]"}, {"code": "H01M10/425", "inventive": true, "first": true, "tree": "[]"}, {"code": "H02J50/10", "inventive": true, "first": true, "tree": "[]"}, {"code": "H04M1/271", "inventive": true, "first": false, "tree": "[]"}, {"code": "H01M10/46", "inventive": true, "first": false, "tree": "[]"}, {"code": "H01M2220/30", "inventive": false, "first": false, "tree": "[]"}, {"code": "H04M2250/74", "inventive": false, "first": false, "tree": "[]"}, {"code": "H02J50/80", "inventive": true, "first": false, "tree": "[]"}, {"code": "H01M2010/4278", "inventive": false, "first": false, "tree": "[]"}, {"code": "Y02E60/10", "inventive": false, "first": false, "tree": "[]"}, {"code": "H04M3/42204", "inventive": true, "first": false, "tree": "[]"}, {"code": "H02J7/0047", "inventive": true, "first": false, "tree": "[]"}, {"code": "H04M3/42204", "inventive": true, "first": false, "tree": "[]"}, {"code": "H02J50/40", "inventive": true, "first": false, "tree": "[]"}, {"code": "H04M1/271", "inventive": true, "first": false, "tree": "[]"}, {"code": "H04M2250/74", "inventive": false, "first": false, "tree": "[]"}, {"code": "H01M50/10", "inventive": true, "first": false, "tree": "[]"}, {"code": "H02J7/0027", "inventive": true, "first": true, "tree": "[]"}, {"code": "H02J50/80", "inventive": true, "first": false, "tree": "[]"}, {"code": "H02J7/027", "inventive": true, "first": false, "tree": "[]"}, {"code": "H04M1/72412", "inventive": false, "first": false, "tree": "[]"}, {"code": "H04M1/72409", "inventive": true, "first": false, "tree": "[]"}]
Family ID: 71072970