PATENT DOCUMENT

Publication Number: US-9948109-B2
Application Number: US-201615161420-A
Country: US
Kind Code: B2

Title: Power management systems for accepting adapter and solar power in electronic devices

Abstract:
The disclosed embodiments provide a power management system that supplies power to components in an electronic device. The power management system includes a system microcontroller (SMC) and a charger. During operation, the power management system accepts power from at least one of a power adapter and a solar panel. Next, the power management system supplies the power to components in the electronic device without using a converter circuit between the solar panel and the power management system.

Claims:
What is claimed is: 
     
       1. A power management system for managing power from a solar panel and a power adapter to power an electronic device, the power management system comprising:
 a power stage configured to process electricity from a solar panel and from a power adapter to power an electronic device; and 
 a controller coupled to the power stage, the controller implementing one or more control loops to control the power stage based on whether the solar panel, the power adapter, or both are coupled to the power stage, 
 wherein responsive to receiving power from the solar panel, an input voltage of the power stage is adjusted at a first rate and a first step size based on an output power from the solar panel and at a second rate and a second step size based on an output power from the power stage. 
 
     
     
       2. The power management system of  claim 1 , wherein the power management system is further configured to track a maximum power point of the solar panel. 
     
     
       3. The power management system of  claim 2 , wherein the power management system is further configured to:
 disable the tracking of the maximum power point of the solar panel responsive to receiving power from the power adapter. 
 
     
     
       4. The power management system of  claim 1 ,
 wherein the output power from the solar panel is determined based on the input voltage of the power stage and an input current of the power stage. 
 
     
     
       5. The power management system of  claim 1 ,
 wherein the output power from the power stage is determined based on an output current of the power stage. 
 
     
     
       6. The power management system of  claim 1 , wherein the first rate is smaller than the second rate and the first step size is larger than the second step size. 
     
     
       7. The power management system of  claim 1 , wherein the second rate is determined based in part on the first rate and the second step size is determined based in part on the first step size. 
     
     
       8. The power management system of  claim 1 , wherein the controller comprises a charger controller coupled to the power stage implementing the one or more control loops and a system controller coupled to the charger controller, the system controller responsive to an assessment of the availability and type of connected power source to manage the powering of the electronic device. 
     
     
       9. A method for supplying power to an electronic device, comprising:
 using a power stage to process power received by the power stage to power the electronic device, wherein the power stage is configured to receive power from a solar panel and from a power adapter; 
 responsive to receiving power from a solar panel, adjusting an input voltage of the power stage at a first rate and a first step size based on an output power from the solar panel and at a second rate and a second step size based on an output power from the power stage. 
 
     
     
       10. The method of  claim 9 , further comprising tracking a maximum power point of the solar panel. 
     
     
       11. The method of  claim 10 , further comprising:
 disabling the tracking of the maximum power point of the solar panel responsive to receiving power from the power adapter. 
 
     
     
       12. The method of  claim 9 ,
 wherein the output power from the solar panel is determined based on the input voltage of the power stage and an input current of the power stage. 
 
     
     
       13. The method of  claim 9 ,
 wherein the output power from the power stage is determined based on an output current of the power stage. 
 
     
     
       14. The method of  claim 9 , wherein the first rate is smaller than the second rate and the first step size is larger than the second step size. 
     
     
       15. The method of  claim 9 , wherein the second rate is determined based in part on the first rate and the second step size is determined based in part on the first step size. 
     
     
       16. A non-transitory computer readable medium comprising instructions stored thereon to cause a computer system to:
 use a power stage to process power received by the power stage to power the computer system, wherein the power stage is configured to receive power from a solar panel and from a power adapter; 
 adjust an input voltage of the power stage, responsive to receiving power from a solar panel, at a first rate and a first step size based on an output power from the solar panel and at a second rate and a second step size based on an output power from the power stage; and 
 power a component of an electronic device using power received from at least one of the solar panel and the power adapter. 
 
     
     
       17. The non-transitory computer readable media of  claim 16 , further comprising instructions to cause the computer system to track a maximum power point of the solar panel. 
     
     
       18. The non-transitory computer readable media of  claim 17 , further comprising instructions to cause the computer system to:
 disable the tracking of the maximum power point of the solar panel responsive to receiving the power from the power adapter. 
 
     
     
       19. The non-transitory computer readable media of  claim 16 ,
 wherein the output power from the solar panel is determined based on the input voltage of the power stage and an input current of the power stage. 
 
     
     
       20. The non-transitory computer readable media of  claim 16 ,
 wherein the output power from the power stage is determined based on an output current of the power stage. 
 
     
     
       21. The non-transitory computer readable media of  claim 16 , wherein the first rate is smaller than the second rate and the first step size is larger than the second step size.

Description:
RELATED APPLICATION 
     This application hereby claims benefit to U.S. Non-Provisional application Ser. No. 13/597,452, filed 29 Aug. 2012, which claims benefit to U.S. Provisional Application No. 61/639,735, filed 27 Apr. 2012, the entire chain of application incorporated by reference. 
    
    
     BACKGROUND 
     Field 
     The disclosed embodiments relate to power sources for electronic devices. More specifically, the disclosed embodiments relate to power management systems in electronic devices for accepting power from power adapters and/or solar panels. 
     Related Art 
     Rechargeable batteries are presently used to provide power to a wide variety of portable electronic devices, including laptop computers, tablet computers, mobile phones, personal digital assistants (PDAs), digital music players, and cordless power tools. The most commonly used type of rechargeable battery is a lithium battery, which can include a lithium-ion or a lithium-polymer battery. 
     During operation, a portable electronic device may be connected to a power adapter that converts alternating current (AC) mains electricity into direct current (DC) and/or a voltage compatible with the battery and/or components of the portable electronic device. Power from the power adapter may then be used to charge the battery and/or supply power to components in the portable electronic device. In the absence of the power adapter and/or mains electricity, the portable electronic device may be powered by the battery until the battery is fully discharged. Because the battery has a limited runtime, operation of the portable electronic device may generally be dependent on the availability of mains electricity. 
     Hence, use of portable electronic devices may be facilitated by improving access to power sources for the portable electronic devices. 
     SUMMARY 
     The disclosed embodiments provide a power management system that supplies power to components in an electronic device. The power management system includes a system microcontroller (SMC) and a charger. During operation, the power management system accepts power from at least one of a power adapter and a solar panel. Next, the power management system supplies the power to components in the electronic device without using a converter circuit between the solar panel and the power management system. 
     In some embodiments, using the power management system to supply the power to the components involves tracking a maximum power point of the solar panel. 
     In some embodiments, tracking the maximum power point of the solar panel involves measuring one or more output powers associated with at least one of the solar panel and the power management system, and adjusting an input voltage of the power management system based on the one or more output powers. For example, the input voltage may be adjusted based on the output power(s) using a perturb-and-observe technique and/or an incremental conductance technique. 
     In some embodiments, measuring the one or more output powers involves at least one of:
         (i) calculating a first output power of the solar panel based on the input voltage and an input current to the power management system; and   (ii) tracking a second output power of the power management system by measuring an inductor current of an inductor in the power management system.       

     In some embodiments, the first output power is calculated using a system microcontroller (SMC) of the power management system, and the second output power is tracked using a charger of the power management system. 
     In some embodiments, the charger includes an analog circuit. The analog circuit may track the maximum power point of the solar panel at a much faster rate than the SMC. 
     In some embodiments, adjusting the output voltage of the power management system based on the one or more output powers involves at least one of:
         (i) adjusting the input voltage at a first rate and a first step size based on the first output power; and   (ii) adjusting the input voltage at a second rate that is higher than the first rate and a second step size that is smaller than the first step size based on the second output power.       

     In some embodiments, the inductor current is measured using at least one of a DCR sensing technique, a resistor sensing technique, a transformer sensing technique, a field effect transistor (FET) sensing technique, and an on-resistance sensing technique. 
     In some embodiments, the electronic device is at least one of a laptop computer, a tablet computer, a portable media player, and a mobile phone. 
    
    
     
       BRIEF DESCRIPTION OF THE FIGURES 
         FIG. 1  shows a schematic of a system in accordance with the disclosed embodiments. 
         FIG. 2  shows a power management system for supplying power to components in an electronic device in accordance with the disclosed embodiments. 
         FIG. 3  shows a power management system for supplying power to components in an electronic device in accordance with the disclosed embodiments. 
         FIG. 4  shows a power management system for supplying power to components in an electronic device in accordance with the disclosed embodiments. 
         FIG. 5  shows a flowchart illustrating the process of tracking a maximum power point of a solar panel in accordance with the disclosed embodiments. 
         FIG. 6  shows a flowchart illustrating the process of supplying power to components in an electronic device in accordance with the disclosed embodiments. 
     
    
    
     In the figures, like reference numerals refer to the same figure elements. 
     DETAILED DESCRIPTION 
     The following description is presented to enable any person skilled in the art to make and use the embodiments, and is provided in the context of a particular application and its requirements. Various modifications to the disclosed embodiments will be readily apparent to those 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. Thus, the present invention is not limited to the embodiments shown, but is to be accorded the widest scope consistent with the principles and features disclosed herein. 
     The data structures and code described in this detailed description are typically stored on a computer-readable storage medium, which may be any device or medium that can store code and/or data for use by a computer system. The computer-readable storage medium includes, but is not limited to, volatile memory, non-volatile memory, magnetic and optical storage devices such as disk drives, magnetic tape, CDs (compact discs), DVDs (digital versatile discs or digital video discs), or other media capable of storing code and/or data now known or later developed. 
     The methods and processes described in the detailed description section can be embodied as code and/or data, which can be stored in a computer-readable storage medium as described above. When a computer system reads and executes the code and/or data stored on the computer-readable storage medium, the computer system performs the methods and processes embodied as data structures and code and stored within the computer-readable storage medium. 
     Furthermore, methods and processes described herein can be included in hardware modules or apparatus. These modules or apparatus may include, but are not limited to, an application-specific integrated circuit (ASIC) chip, a field-programmable gate array (FPGA), a dedicated or shared processor that executes a particular software module or a piece of code at a particular time, and/or other programmable-logic devices now known or later developed. When the hardware modules or apparatus are activated, they perform the methods and processes included within them. 
     The disclosed embodiments provide a method and system for supplying power to components in an electronic device such as a personal computer, laptop computer, tablet computer, personal digital assistant (PDA), mobile phone, and/or portable media player. As shown in  FIG. 1 , an electronic device  102  may be connected to an external power adapter  104  that converts alternating current (AC) mains electricity into direct current (DC) and/or a voltage that can be used to charge a battery of electronic device  102  and/or operate components in electronic device  102 . For example, electronic device  102  may be connected to power adapter  104  using a Universal Serial Bus (USB) connector, MagSafe (MagSafe™ is a registered trademark of Apple Inc.) connector, and/or other type of power connector. 
     However, power adapter  104  may only supply power to the battery and/or components of electronic device  102  while power adapter  104  is connected to mains electricity (e.g., through a power outlet). In the absence of power adapter  104  and/or mains electricity, electronic device  102  may be powered by the battery until the battery is fully discharged. Consequently, electronic device  102  may have limited operability if mains power and/or power adapter  104  are unavailable for extended periods. 
     In one or more embodiments, electronic device  102  includes functionality to accept power from a solar panel  106  in lieu of and/or in addition to power from power adapter  104 . Like power adapter  104 , solar panel  106  may connect to electronic device  102  through a USB connector, MagSafe connector, and/or other power connector. Electricity from solar panel  106  may then be used to charge the battery in electronic device  102  and/or power the components of electronic device  102 . For example, solar panel  106  may supply power to electronic device  102  through a MagSafe connector if power adapter  104  and/or mains electricity are not available. On the other hand, both solar panel  106  and power adapter  104  may be connected to electronic device  102  through separate USB interfaces and supply power to the battery and/or components of electronic device  102  at the same time. 
     In addition, a power management system in electronic device  102  may be configured to accept power from solar panel  106  without using a converter circuit between solar panel  106  and the power management system. In other words, the power management system may operate within electronic device  102  to convert power from solar panel  106  into a voltage, current, and/or form that are compatible with the battery and/or components of electronic device  102 . The power management system may thus increase the portability of electronic device  102  while facilitating access to an alternative power source (e.g., solar panel  106 ) for electronic device  102 . Power management systems for supplying power from solar panels to components of electronic devices are described in further detail below with respect to  FIGS. 2-4 . 
       FIG. 2  shows a power management system for supplying power to components in electronic device  102  in accordance with the disclosed embodiments. As mentioned above, the power management system may accept power from a power source  200  such as a power adapter (e.g., power adapter  104  of  FIG. 1 ) or solar panel (e.g., solar panel  106  of  FIG. 1 ). The power management system may then supply the power to a battery  222  and/or a set of components  220  (e.g., processor, memory, display, keyboard, radio, etc.) in electronic device  102  without using a converter circuit between the solar panel and the power management system. 
     As shown in  FIG. 2 , the power management system includes a charger  202  and a system microcontroller (SMC)  212 . Charger  202  includes a power stage  204  and a charger integrated circuit (IC)  206  that process electricity from power source  200  into a form (e.g., voltage, current, DC, etc.) that is compatible with components  220  and/or battery  222 . For example, power stage  204  may include an inductor, a capacitor, one or more field effect transistors (FETs), and/or other components of a buck converter. Charger IC  206  may include a controller  208  that implements an input current loop, a battery current loop, an output voltage loop, and/or an input voltage loop for controlling the charging of battery  222  and/or powering of components  220  using power from power source  200 . 
     SMC  212  may monitor and/or manage the charging of battery  222  and/or powering of components  220  using power from power source  200 . For example, SMC  212  may correspond to a microprocessor that assesses the availability and type (e.g., power adapter, solar panel) of power source  200 , as well as the state of charge, capacity, and/or health of battery  222 . SMC  212  may then manage the charging or discharging of battery  222  and/or powering of components  220  based on the assessment of power source  200  and battery  222 . 
     In one or more embodiments, charger  202  and SMC  212  supply power from the solar panel to components  220  and/or battery  222  by tracking a maximum power point of the solar panel. First, SMC  212  may calculate an output power of the solar panel from an input current  214  and an input voltage  216  to the power management system. For example, SMC  212  may obtain the output power of the solar panel by multiplying current  214  and voltage  216 . 
     Next, SMC  212  may generate a signal  218  that is used by charger  202  to adjust voltage  216 . Signal  218  and voltage  216  may be received by an operational amplifier (op-amp)  210  in charger IC  206  and used in the input voltage loop to optimize the processing of power from the solar panel. For example, signal  218  may be used by charger IC  206  to update a reference voltage (e.g., maximum power point voltage) of the input voltage loop using a perturb-and-observe technique, an incremental conductance technique, and/or another maximum point power tracking (MPPT) technique. Conversely, if power source  200  is a power adapter, charger IC  206  may disable the input voltage loop and use the input current loop, battery current loop, and output voltage loop to supply power from the power adapter to components  220  and/or battery  222 . 
     Those skilled in the art will appreciate that MPPT of the solar panel may be adversely impacted by the rate at which SMC  212  updates signal  218 . For example, SMC  212  may correspond to a low-power microprocessor that is not capable of updating signal  218  more than once every second. As a result, SMC  212  may be too slow to efficiently and/or effectively track the maximum power point of the solar panel. To mitigate issues associated with implementing MPPT on SMC  212 , MPPT may also be performed by charger  202 , as discussed in further detail below with respect to  FIG. 3 . 
       FIG. 3  shows a power management system for supplying power to components in electronic device  102  in accordance with the disclosed embodiments. Like the power management system of  FIG. 2 , the power management system of  FIG. 3  accepts power from a power source  300 , such as a power adapter and/or solar panel, and supplies the power to components  320  and/or a battery  322  of electronic device  102 . However, MPPT for the solar panel may be performed by a charger  302  in the power management system instead of an SMC (e.g., SMC  212  of  FIG. 2 ). 
     As shown in  FIG. 3 , charger  302  includes a power stage  304  and a charger IC  306 . Power stage  304  may include an inductor, a capacitor, one or more FETs, and/or other components of a buck converter that converts power from power source  300  into a form that can be used to charge battery  322  and/or operate components  320 . 
     Within charger IC  306 , a MPPT circuit  324  may track an output power of the power management system by measuring an inductor current  326  of the inductor in power stage  304 . More specifically, the output power of the power management system may be calculated as the product of the output voltage and output current of the power management system. Assuming the buck converter in power stage  304  operates in steady state, the output current of the power management system equals current  326 . In addition, the output voltage of the power management system may be coupled to the voltage of battery  322 , which changes very slowly. Thus, changes to the output power may be reflected in current  326 , assuming the voltage of battery  322  is constant. 
     Those skilled in the art will appreciate that the power management system and/or MPPT circuit  324  may use a variety of techniques to measure current  326  from the inductor. For example, the power management system and/or MPPT circuit  324  may use a resistor-capacitor (RC) circuit to perform DCR sensing of the voltage across the inductor and calculate current  326  from the measured voltage. Alternatively, the power management system and/or MPPT circuit  324  may measure the on-resistance from drain to source (R DS(on)  of a low-side FET in power stage  304  and obtain current  326  from the measured on-resistance. Finally, the power management system and/or MPPT circuit  324  may use a transformer sensing technique and/or a resistor sensing technique to obtain current  326 . 
     Next, MPPT circuit  324  may use current  326  to generate a signal  318  that is inputted to an op-amp  310 , along with an input voltage  316  to the power management system. Signal  318  and voltage  316  may then be used by charger IC  306  and/or a controller  308  in charger IC  306  to track the maximum power point of the solar panel. For example, charger IC  306  may adjust a reference voltage of an input voltage loop in charger  302  based on signal  318  and voltage  316 . 
     Because the output power is tracked by measuring a single value (e.g., the inductor current), components such as microprocessors, multipliers, and/or analog-to-digital (A/D) converters may not be required in MPPT circuit  324 . Instead, MPPT circuit  324  may be an analog circuit that tracks the maximum power point of the solar panel at a much faster rate than the rate of change of voltage from battery  322  and/or the rate at which the SMC performs MPPT. In addition, MPPT circuit  324  may track the maximum output power point of the power management system, which may be more accurate than tracking of the maximum input power point of the power management system (e.g., using the SMC). Finally, MPPT may be performed by both MPPT circuit  324  and the SMC to further facilitate power production using the solar panel, as discussed in further detail below with respect to  FIG. 4 . 
       FIG. 4  shows a power management system for supplying power to components in electronic device  102  in accordance with the disclosed embodiments. The power management system of  FIG. 4  may accept power from a power source  400  such as a power adapter and/or solar panel. If the solar panel is connected to electronic device  102 , a charger  402  and/or an SMC  412  in the power management system may track the maximum power point of the solar panel and supply the power to a set of components  420  and/or a battery  422  in electronic device  102  without using a converter circuit between the solar panel and the power management system. 
     In particular, SMC  412  may calculate a first output power of the solar panel based on an input voltage  416  and an input current  414  to the power management system, as discussed above with respect to  FIG. 2 . SMC  412  may then adjust voltage  416  at a first rate and a first step size based on the first output power. For example, SMC  412  may use an incremental conductance technique to precisely set the maximum power point of the solar panel at a relatively slow rate, thus enabling periodic precise adjustments to the output voltage of the power management system and/or maximum power point. 
     Charger  402  may track a second output power of the power management system by measuring an inductor current  426  of an inductor in a power stage  404  of charger  402 , as discussed above with respect to  FIG. 3 . An MPPT circuit  424  (e.g., an analog circuit) in charger  402  may then adjust voltage  416  at a second rate and a second step size based on the second output power. In addition, the second rate may be higher than the first rate, and the second step size may be smaller than the first step size. 
     By making frequent, fine-grained adjustments to voltage  416 , MPPT circuit  424  may facilitate accurate tracking of the solar panel&#39;s maximum power point in between larger, less frequent adjustments to voltage  416  by SMC  412 . For example, changes to the output voltage from SMC  412  may be received every second by MPPT circuit  424  and transmitted using a signal  418  to an op-amp  410  in a charger IC  406  of charger  402 . Charger IC  406  and/or a controller  408  in charger IC  406  may then use signal  418  and voltage  416  to precisely update the reference voltage of an input voltage loop implemented by charger IC  406 . While SMC  412  calculates the next adjustment to voltage  416  using current  414  and voltage  416 , MPPT circuit  424  may measure current  426  and incrementally update signal  418  based on current  426 . 
     To further facilitate tracking of the maximum power point, SMC  412  and MPPT circuit  424  may coordinate adjustments to voltage  416 . For example, the step size and/or rate used by MPPT circuit  424  to adjust voltage  416  may be based on the technique (e.g., perturb-and-observe, incremental conductance, etc.), step size, and/or rate used by SMC  412  to adjust voltage  416 . Alternatively, SMC  412  and MPPT circuit  424  may execute independently from one another and adjust voltage  416  based on current  414 , voltage  416 , and/or current  426 . 
     As mentioned above, the solar panel may operate as power source  400  to electronic device  102  without requiring an additional converter circuit between the solar panel and the power management system. Instead, existing parts of the power management system (e.g., charger  402 , SMC  412 ) may be modified to convert power from the solar panel and perform MPPT on the power. In turn, the power management system may represent a size and/or weight savings over conventional power management systems that connect power sources directly to components in electronic devices and require separate (e.g., external) converter circuits to convert power from solar panels into a form that can be used by the components. 
       FIG. 5  shows a flowchart illustrating the process of tracking a maximum power point of a solar panel in accordance with the disclosed embodiments. In one or more embodiments, one or more of the steps may be omitted, repeated, and/or performed in a different order. Accordingly, the specific arrangement of steps shown in  FIG. 5  should not be construed as limiting the scope of the embodiments. 
     Initially, an output power of the solar panel and/or a power management system that accepts power from the solar panel is measured (operation  502 ). The output power may be calculated based on an input voltage and input current to the power management system. For example, the output power may be calculated as the product of the input voltage and the input current. Alternatively, the output power may be tracked by measuring an inductor current of an inductor in the power management system. For example, the inductor current may be obtained using a DCR sensing technique, a resistor sensing technique, a transformer sensing technique, a FET sensing technique, and/or an on-resistance (e.g., R DS(on) ) sensing technique. 
     Tracking of the maximum power point may be based on changes to the output power and/or input voltage to the power management system (operation  504 - 508 ). If the output power has increased, the input voltage may be adjusted in the same direction as that of the previous iteration of MPPT. In particular, the input voltage may be increased (operation  510 ) if the input voltage was increased in the previous MPPT iteration and decreased (operation  512 ) if the input voltage was decreased in the previous MPPT iteration. 
     Conversely, if the output power has decreased, the input voltage may be adjusted in the opposite direction from that of the previous MPPT iteration. In other words, the input voltage may be decreased (operation  514 ) if the input voltage was increased in the previous MPPT iteration and increased (operation  516 ) if the input voltage was decreased in the previous MPPT iteration. 
     The change in input voltage may additionally be based on the technique used to measure the output power in operation  502  and/or track the maximum power point of the solar panel. For example, a perturb-and-observe technique may adjust the input voltage using a relatively large step size if the output power is calculated from the input voltage and input current. On the other hand, the perturb-and-observe technique may adjust the input voltage using a relatively small step size if the output power is tracked using the inductor current. Finally, an incremental conductance technique may precisely calculate the step size required to adjust the input voltage so that the solar panel is operating at the maximum power point. 
       FIG. 6  shows a flowchart illustrating the process of supplying power to components in an electronic device in accordance with the disclosed embodiments. In one or more embodiments, one or more of the steps may be omitted, repeated, and/or performed in a different order. Accordingly, the specific arrangement of steps shown in  FIG. 6  should not be construed as limiting the scope of the embodiments. 
     First, a power management system is provided in the electronic device for accepting power from a power adapter and/or a solar panel (operation  602 ). The power management system may include an SMC and a charger. Next, the power management system is used to supply power to the components without using a converter circuit between the solar panel and the power management system (operation  604 ). For example, the SMC and/or charger may convert power from the solar panel into a form that is compatible with the battery and/or components, thus enabling omission of the converter circuit between the solar panel and power management system. 
     The SMC and/or charger may also track the maximum power point of the solar panel. For example, the SMC and/or charger may measure one or more output powers associated with at least one of the solar panel and the power management system and adjust an input voltage of the power management system based on the one or more output powers. The SMC may calculate a first output power of the solar panel based on the input voltage and an input current to the power management system, and an analog circuit in the charger may track a second output power of the power management system by measuring an inductor current of an inductor in the power management system. The SMC may then adjust the input voltage at a first rate and a first step size based on the first output power, and the analog circuit may adjust the input voltage at a second rate that is higher than the first rate and a second step size that is smaller than the first step size based on the second output power. 
     The foregoing descriptions of various embodiments have been presented only for purposes of illustration and description. They are not intended to be exhaustive or to limit the present invention to the forms disclosed. Accordingly, many modifications and variations will be apparent to practitioners skilled in the art. Additionally, the above disclosure is not intended to limit the present invention.

Metadata:
Filing Date: 20160523
Publication Date: 20180417
Grant Date: 20180417
Priority Date: 20120427
Inventors: LEE, KISUN
PANDYA, MANISHA P.
ELKAYAM, SHIMON
Assignee: APPLE INC
CPC Classifications: [{"code": "G06F1/263", "inventive": true, "first": false, "tree": "[]"}, {"code": "H02J3/385", "inventive": true, "first": true, "tree": "[]"}, {"code": "Y10T307/696", "inventive": false, "first": false, "tree": "[]"}, {"code": "G06F1/266", "inventive": true, "first": false, "tree": "[]"}, {"code": "G06F1/263", "inventive": true, "first": true, "tree": "[]"}, {"code": "Y02E10/56", "inventive": false, "first": false, "tree": "[]"}, {"code": "G06F1/266", "inventive": true, "first": false, "tree": "[]"}, {"code": "G06F1/263", "inventive": true, "first": true, "tree": "[]"}]
Family ID: 49478441