Patent Publication Number: US-2016226283-A1

Title: Apparatus and method to change current limit

Description:
BACKGROUND 
     1. Field 
     Embodiments may relate to an electronic device and a power source. 
     2. Background 
     An electronic device may utilize a charger (or charging system) in order to provide power. One type of charger is a universal serial bus (USB) charger. There are many different types of USB chargers and different type of protocols. As one example, USB 2.0/3.0 protocol may specify a nominal voltage at 5 volts (V) and a current may be limited to less than 500 milliamps (mA)/900 mA per port. In another example, USB Battery Charging (BC) 1.2 protocol may specify a nominal voltage of 5 V and a maximum allowable current of 1.5 amps (A) per port. However, these power limits may be not sufficient for all electronic devices or platforms. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Arrangements and embodiments may be described in detail with reference to the following drawings in which like reference numerals refer to like elements and wherein: 
         FIG. 1  shows an electronic device according to an example embodiment; 
         FIG. 2  shows a USB power source according to an example embodiment; 
         FIG. 3  is a flowchart to show providing a source identifier according to an example embodiment; 
         FIG. 4  is a flowchart to show detecting a source identifier according to an example embodiment; 
         FIG. 5  shows a power source and an electronic device (or platform) according to an example embodiment; and 
         FIG. 6  shows a power source and an electronic device (or platform) according to an example embodiment. 
     
    
    
     DETAILED DESCRIPTION 
     In the following detailed description, like numerals and characters may be used to designate identical, corresponding and/or similar components in differing figure drawings. Further, in the detailed description to follow, example sizes/models/values/ranges may be provided although embodiments are not limited to the same. Where specific details are set forth in order to describe example embodiments, it should be apparent to one skilled in the art that embodiments may be practiced without these specific details. 
     An electronic device may be any one of a mobile terminal, a mobile device, a mobile computing platform, a mobile platform, a laptop computer, a tablet, an ultra-mobile personal computer, a mobile Internet device, a smartphone, a personal digital assistant, a display device, a television (TV), etc. As one example, an electronic device may be a mobile platform. 
     The electronic device may include a port to receive an input voltage (or power) and/or to provide an output power. The electronic device may include a charger. The charger may include a voltage regulator (of the electronic device) to provide an output voltage to a load. The voltage regulator may provide a regulated output voltage for the load. As one example, the load may include a display device, a processor, a controller, etc. 
     The charger may also (or alternatively) provide an output voltage to a battery (provided at the electronic device). The battery may be charged by the voltage received from the charger. The charger may provide an output voltage to the load and/or the battery. 
     The electronic device may include a port, such as a USB input port, that may receive (or couple to) a power source or a USB device (e.g. a mouse, a keyboard). The electronic device may detect and automatically perform an appropriate action based on the attached device or power source. 
     The electronic device may utilize Universal Serial Bus (USB) power delivery (PD). A USB charge port of the electronic device may couple to any of a plurality of different devices, including a USB power source. 
     USB PD may enable functionality of USB by providing flexible power delivery along with data over a single cable (or cable assembly). In USB PD, power directions are no longer fixed. Power distribution may therefore be bi-directional. This may enable an electronic device with power (host or client) to provide power to another device. For example, a display with a power source (i.e., an internal battery or a wall socket) may power or charge a laptop or other electronic device. 
     The USB charge port may be used to perform various functions such as a laptop computer charging a mobile device (e.g. phone or tablet), a charger (such as a USB charger) charging a laptop computer and/or a USB PD charger to charge a laptop computer. Other types of functions may also be provided. 
     Devices may be designed and manufactured to comply with a USB PD specification. Components that follow the USB PD specification may include marked cables (or cable assemblies). 
     According to the USB PD specification, a PD Micro-A connector, a PD Micro-AB connector and a PD Micro-B connector may each separately have a 3 amp current limit According to the USB PD specification, a PD Standard-A connector and a PD Standard-B connector may each separately have a 5 amp current limit. However, in order to overwrite the current limit of USB 2.0/3.0 and BC 1.2, a USB PD system may need an expensive power line communication transceiver and/or a bulky isolation inductor. 
     A USB PD system may identify a current limit of a USB PD system when a cable is provided at a default voltage, such a 5 volts. The USB PD default current limit may overwrite current limits of USB 2.0/3.0, BC 1.2 and other USB charging systems using non-PD cable assemblies. For example, a USB PD system with PD Micro-A and PD Micro-B connectors may specify a nominal voltage at 5 volts (V) and 3 amp (A) default current limit, which may overwrite USB 2.0 that specifies a nominal voltage at 5 volts (V) and the maximum allowable current at 500 milliamps (mA). 
     A USB power source and an electronic device may be coupled together by a cable, such as a USB cable. An identification method may be provided that includes a cable detector operation and a source identifier operation. 
     The cable detector operation may relate to USB PD markings on connectors (or plug connectors) to indicate a current capability of the cable (or cable assemblies). The source identifier operation may include providing a source identifier, such as an electrical signature, on D+ and D− pins of the cable to indicate a current limit of the USB power source. 
       FIG. 1  shows an electronic device according to an example embodiment. Other embodiments and configurations may also be provided. 
     More specifically,  FIG. 1  shows an electronic device  10  having a USB sink port  20  (or a USB charge port), a source detector component  23 , a cable detector component  28 , a controller  35 , a battery charger  50  (or charger), a battery  30  and a load  40 . As one example, the USB sink port  20  may have a specific color based on a specific type of the port. With a USB PD charge port, power may flow in either direction (i.e., into the electronic device  10  or out of the electronic device  10 ). 
     An external device such as an electronic device and/or a power source may couple to the USB sink port  20  (or the charge port). The power source may be any type of device to provide power. 
     The sink port  20  may be referred to as a receptacle to receive a connector or a plug of a cable. 
     The source detector component  23  may receive information from the USB sink port  20 , and may provide information to the controller  35 . The cable detector component  28  may receive information from the USB sink port  20 , and may provide information to the controller  35 . 
     The controller  35  may control operations of the electronic device  10 . For example, the controller  35  may control operations of the charger  50 , such as based on inputs to the controller  35 . 
     The battery  30  may be a battery pack, a battery cell and/or a plurality of battery cells, for example. The battery  30  may be provided in a battery port of the electronic device  10 . 
     The charger  50  may be referred to as a bi-directional USB buck-boost charger, for example. The charger  50  may provide operations of a buck converter (or voltage step-up converter) and a boost converter (or voltage step-down converter). The charger  50  may be considered bi-directional since the charger  50  may provide power to the electronic device  10  or draw power from the electronic device  10 . The charger  50  may operate in a boost configuration or may operate in a buck configuration. 
     The load  40  may include various components such as a display device, a processor, etc. 
       FIG. 2  shows a USB power source according to an example embodiment. Other embodiments and configurations may also be provided. 
     More specifically,  FIG. 2  shows a USB power source  60  that includes a power source or battery  62 , a voltage regulator  64 , a controller  66 , a source identifier component  72 , a cable detector component  74  and a USB source port  80 . 
     The cable detector component  74  may receive information from the USB source port  80 , and may provide information to the controller  66 . The source identifier component  72  may receive information from the controller  66 , and may provide information to the USB source port  80 . 
       FIG. 3  is a flowchart to show providing a source identifier according to an example embodiment. Other embodiments, operations and orders of operations may also be provided. As one example, a source identifier may be provided from a USB power source to an electronic device (i.e., a host). The electronic device may be a mobile platform, for example. 
     More specifically,  FIG. 3  shows that a cable detection may be provided in operation  102 . Operation  104  may include a determination of whether a PD cable (or PD cable assembly) is detected. The determination may be based on an electronic marking of the PD cable. For example, in operation  102  for a USB system with a PD Standard-A receptacle may detect a PD Detect pins (i.e., pins  10  and  11 ) closed circuit to a shield when the PD plug (of the cable) is inserted into the receptacle. When a non-PD rated USB Standard-A plug is inserted into the receptacle, then operation  102  may detect a PD Detect pins open circuit. The cable detector component (of the USB power source) may measure (or determine) a circuit connection between the PD Detect pins (of the connector/cable) and the shield, and then identify between PD and non-PD rated plugs in operation  104 . Operation  104  is a determination to provide a source identifier only when a cable with a PD plug(s) is detected or determined. 
     The cable detector component may determine that the cable is a power delivery cable based on an electronic marking of the cable. The electronic marking is based on characteristics of the power detect pins of the power delivery cable. 
     If the determination is that a PD cable (or cable assembly) is detected (i.e., a YES determination), then the USB power source may provide a source identifier in operation  106 . The source identifier may be an electrical signature on D+/D− pins of the cable (or connector), for example. The D+/D− pins are part of the cable/connector, which are intended for data transfer. However, since the D+/D− pins are not used for power deliver in USB PD, embodiments may provide that the D+/D− pins may provide a source identification. 
     The source identifier component may provide a source identifier when the cable is determined to be a power delivery cable. The source identifier may be an electronic signature. The source identifier may be provided over D+/D− pins of the cable. 
     The source identifier may be provided from the USB power source to the electronic device (such as the charge port). The USB power source may overwrite or change the output current limit in operation  108 . As one example, a controller of the USB power source may control a power switch at the USB power source to limit an output current of the power source. The power switch may be a P-channel metal-oxide-silicon field effect transistor (MOSFET), for example, that may be controlled by an output of a comparator (or electronics comparator). Inputs to the comparator may be a measured output current and an output current limit. The comparator may turn off the power switch when the measured output current level exceeds the output current limit. 
     In at least one embodiment, logic, at least a portion of which is hardware, may change an output current limit of the USB power source, and may provide power at a level less than (or up until) the output current limit. The logic may include the controller, the components and/or circuitry to perform the above described operations. 
     On the other hand, if operation  104  determines that a PD cable assembly is not detected (i.e., a NO determination), then in operation  110 , the cable may be determined to be a non-PD rated cable assembly. This may mean not having a high current capability for the coupled devices (i.e., the electronic device and the USB power source), the USB power source may not provide PD current capability and/or no source identifier may be provided to supply a higher default current. 
       FIG. 4  is a flowchart to show detecting a source identifier according to an example embodiment. Other embodiments, operations and orders of operation may also be provided. As one example, the source identifier may be provided from the USB power source to an electronic device (i.e., a host). The electronic device may therefore detect the source identifier. The electronic device may be a mobile platform, for example. 
     More specifically,  FIG. 4  shows that a cable detection may be provided in operation  202 . Operation  204  may include a determination of whether a PD cable (or PD cable assembly) is detected. The determination may be based on an electronic marking of the PD cable. The electronic marking may be an impedance between two pins of the USB connector (of the cable). For example, a PD Micro-B plug capable of 3 amps may have a 10 nanofarads capacitance between an identification (ID) pin and a ground pin. On the other hand, a non-PD Micro-B plug capable of 1.5 amps may have an infinite impedance between the ID pin and the ground pin, and then identify between PD and non-PD rated plugs in operation  204 . Operation  204  is the determination to provide a source identifier only when a cable with a PD plug(s) is detected. 
     If a determination is that a PD cable (or PD cable assembly) is detected (i.e., a YES determination), then the electronic device (or the mobile platform) may detect a source identifier in operation  206 . As one example, the source identifier of the PD cable may be electronic markings. The electronic device (i.e., the mobile platform) may detect the source identifier. 
     In operation  208 , a determination may be made whether the source identifier (or the electrical signature) includes a source identification (ID), which may be on the D+/D− pins of the cable, for example. If a determination is that there is the source identification (i.e., Yes in operation  208 ), then the input current limit of the USB port may be updated (or changed) in operation  210 . For a mobile platform device, a battery charge controller may adjust an input current limit of a USB sink port (i.e., the USB charge port). For example, an embedded controller may read a current limit of the USB port from the source identifier component via a serial interface, and the controller may write the current limit to the battery charge controller. 
     The electronic device may receive power at a limit less than (or up until) the input current limit. 
     In at least one embodiment, logic at least a portion of which is hardware, may change an input current limit of the electronic device based on the determined identification. The logic may include the controller, the components  23 ,  28  and/or circuitry to perform the above-described operations. 
     On the other hand, if operation  204  determines that a PD cable (or cable assembly) is not detected (i.e., a No determination), then in operation  212 , the cable may be determined to be a non-PD rated cable. This may mean the cable is not capable of a higher current and the electronic device shall not draw the PD rated current level. 
     Additionally, if operation  208  determines that a source identification is not contained within the source identifier, then in operation  212 , the cable may be determined to be a non-PD rated cable. 
       FIG. 5  shows a power source and an electronic device according to an example embodiment. Other embodiments and configurations may also be provided. The electronic device may be a platform, such as a mobile platform. 
     More specifically,  FIG. 5  shows a USB power source  300 , a USB source port  350  and a cable  500 . The USB source port  350  may be considered as part of the USB power source  300 . The USB source port  350  may be a USB Standard-A receptacle, for example. The cable  500  may be a USB PD cable to perform power delivery. 
       FIG. 5  also shows an electronic device  400 , a USB source port  450  and the cable  500 . The USB sink port  450  may be considered as part of the electronic device  400 . The USB sink port  450  may be a Micro-B receptacle or a Micro-AB receptacle, for example. 
     As shown in  FIG. 5 , the USB power source  300  may include a controller  310 , a source identifier component  320  and a cable detector component  330 . The controller  310  may control the source identifier component  320 , and the controller  310  may control the cable detector component  330 . The cable detector component  330  may provide information to the controller  310 . The source identifier component  320  may provide information to the USB source port  350 . 
     The source identifier component  320  may correspond to the source identifier component discussed above. The cable detector component  330  may correspond to the cable detector component discussed above. 
     The USB source port  350  may be any one of a number of different types of USB ports, including a Standard-A receptacle and/or a Micro-AB receptacle, for example. 
     As shown in  FIG. 5 , the electronic device  400  may include a controller  410 , a source detector component  420  and a cable detector component  430 . The electronic device  400  may also include a processor, a display, etc. 
     The source detector component  420  may correspond to the source detector component discussed above. The cable detector component  430  may correspond to the cable detector component discussed above. 
     The USB sink port  450  may be any one of a number of different types of USB ports, including a Micro-B receptacle and/or a Micro A/B receptacle, for example. 
     The cable detector component  330  (of the USB power source  300 ) may detect when a PD rated plug (of the cable  500 ) is inserted into the USB source port  350  of the power source  300 . The cable detector component  330  may then communicate with the controller  310  to indicate that the PD rated plug (of the cable  500 ) is coupled to the USB source port  350  and the USB power source  300 . The controller  310  may then inform the source identifier component  320 . 
     The source identifier component  320  may then provide an electrical signature to the USB source port  350  (and then the cable  500 ). The electrical signature may be provided thru the cable  500  and to the source detector component  420  of the electronic device  400 . The electrical signature may be provided by using a resistor network, for example. The electrical signature may represent the high current capability of the USB power source  300 . The controller  310  may read or determine that the cable is PD rated and notify the source identifier component  320  to indicate high current capability to the far end electronic device. The electrical signature may be provided from the resistor network (of the source identifier component  320 ) and across the D+/D− pins of the cable  500 . The electronic signature may be based on the USB power source  300  capability of providing a high current when a PD cable is detected or determined. 
     The cable detector component  430  (of the electronic device  400 ) may detect when a PD rated plug (of the cable  500 ) is inserted to the USB sink port  450  of the electronic device  400 . The cable detector component  430  may then communicate with the controller  410  to indicate that the PD rated plug (of the cable  500 ) is coupled to the electronic device  400 . The controller  410  may then inform the source detector component  420 . 
     The source detector component  420  may receive the electronic signature from the USB power source  300 . For example, the source detector component  420  may receive the electronic signature from the D+/D− pins of the cable  500 . The source detector component  420  may include circuitry that includes voltage and impedance measuring circuits. For example, the source detector component  420  may measure electrical signature across the D+/D− pins, which may be voltage levels or impedances. 
     Based on the received identification, a controller may control an input current limit of the electronic device  400 . 
       FIG. 6  shows a power source and an electronic device according to an example embodiment. Other embodiments and configurations may also be provided. The electronic device may be a platform, such as mobile platform. The  FIG. 6  diagram is intended to show further details of the  FIG. 5  configuration. 
     More specifically,  FIG. 6  shows the USB power source  300 , the USB source port  350 , the electronic device  400  and the USB sink port  450  in more detail. Other configurations may also be provided. 
       FIG. 6  shows one embodiment of details of the controller  310 , the source identifier component  320  and the cable detector component  330 . 
     In  FIG. 6 , the USB source port  350  may receive a USB PD std-A connector, and the USB sink port  450  may receive a USB PD micro-B connector. A USB PD cable may be provided between the USB source port  350  and the USB sink port  450 . 
     As shown, the controller  310  may provide signals on signal lines corresponding to the D+/D− pins of the cable  500 . The D+ pin may be Pin  2 , and the D− pin may be Pin  3 , for example. 
     The source identifier component  320  may include a resistor network  325  having a plurality of resistors R 1 , R 2 , R 3 , R 4 , R 5 . Other resistors, resistor configurations or circuits may be provided as the source identifier component  320 . 
     The source identifier component  320  may provide an electrical signature on Vbus, which may correspond to Pin  1 . 
     The cable detector component  330  may detect that the cable  500  (and plug) is coupled to the source port  350  of the power source  300 . The cable detector component  330  may be coupled to Pins  10  and  11  of the plug, which may serve as PD detect pins. 
     As shown in  FIG. 6 , the plug (to couple to the source port  350 ) may include Vbus on Pin  1 , D+ on Pin  2 , D− on Pin  3 , a Ground on Pin  4  and PD detect on Pins  10 ,  11 . Other configurations may be provided. 
     The plug (to couple to the sink port  450 ) may include Vbus on Pin  1 , D+ on Pin  2 , D− on Pin  3 , a Ground (GND) on Pin  5 , an ID on Pin  4 . 
     The source detector component  420  may receive D+ inputs from Pin  2  and D− inputs from Pin  3 . The source detector component  420  may determine the electric signature based on D+/D− inputs. 
     The cable detector component  430  may receive inputs from Pin  5  and Pin  4  to detect an electronic marking (or marker). For example, the cable detector component  430  may determine impedance across the pins by measuring a voltage across the pins when an electric current at varying frequency levels is injected through the pins. 
     As shown in  FIG. 6 , the electrical signature on the D+/D− pins may be provided using the resistor network (R 1 , R 2 , R 3 , R 4 , R 5 ). The voltage across D+/D− pins may be less than 3.3V. The source detector component  420  may include voltage and impedance measurement circuitries. 
     In at least one embodiment, a computer-readable medium may store a program for controlling circuitry of the electronic devices (including the USB power source). The circuitry may be controlled to control components of the USB power source  300  or the electronic device  400 . The program may be used by (or rather than) the controller  310  and/or the controller  410  (or processors). The program may be stored in a system memory, which for example, may be internal or external. In at least one embodiment, the program may be part of a control algorithm for controlling operations of the USB power source  300  or the electronic device  400 . 
     Instructions or code executed by the controllers may be provided to a memory from a machine-accessible medium, or an external storage device accessible via a remote connection (e.g. over a network via an antenna and/or network interface) providing access to one or more electronically-accessible media, etc. A machine-accessible medium may include any mechanism that provides (i.e., stores and/or transmits) information in a form readable by a machine (e.g., a computer). For example, a machine-accessible medium may include random access memory (RAM), read only memory (ROM), magnetic or optical storage medium, flash memory devices, electrical, optical, acoustical or other form of propagated signals (e.g., carrier waves, infrared signals, digital signals), etc. In alternative embodiments, hard-wired circuitry may be used in place of or in combination with the instructions or code, and thus the embodiments are not limited to any specific combination of hardware circuitry and software instructions. 
     The program may include code or instructions to perform any of the operations or functions performed in embodiments previously discussed above. 
     The following examples pertain to further embodiments. 
     Example 1 is an electronic device to change an input current limit comprising: a port to receive a plug of a cable, a cable detector component to detect the plug to couple to the port, a source detector component to determine an identification of a power source, and logic, a portion of which is hardware, to change an input current limit of the electronic device based on the determined identification. 
     In Example 2 the subject matter of Example 1 can optionally include that the cable detector component to determine the cable is a power delivery cable based on an electronic marking of the cable. 
     In Example 3 the subject matter of Example 2 can optionally include that the electronic marking is based on characteristics of an identification pin and a ground pin of the power delivery cable. 
     In Example 4 the subject matter of Example 2 can optionally include that the source detector component to determine a source identifier when the cable is determined to be a power delivery cable. 
     In Example 5 the subject matter of Example 4 can optionally include that the source identifier to be determined based an electronic signature. 
     In Example 6 the subject matter of Example 4 can optionally include that the source identifier to be provided on D+/D− pins of the cable. 
     In Example 7 the subject matter of Example 4 can optionally include that the source identifier to be provided over the cable between the power source and the electronic device. 
     In Example 8 the subject matter of Example 1 can optionally include that the logic includes a controller to change the input current limit of the electronic device. 
     In Example 9 the subject matter of Example 1 can optionally include that the electronic device to receive power at a current limit less than the input current limit. 
     In Example 10 the subject matter of Example 1 can optionally include that the port is a universal serial bus (USB) port. 
     Example 11 is an electronic device to change an output current limit, comprising: a port to receive a plug of a cable, a cable detector component to detect the plug to couple to the port, a source identifier component to provide an identification of the electronic device, and logic, at least a portion of which is hardware, to change an output current limit of the electronic device, and to provide power at a level less than the output current limit. 
     In Example 12 the subject matter of Example 11 can optionally include that the cable detector component to determine the cable is a power delivery cable based on an electronic marking of the cable. 
     In Example 13 the subject matter of Example 12 can optionally include that the electronic marking is based on characteristics of power detect pins of the power delivery cable. 
     In Example 14 the subject matter of Example 12 can optionally include that the source identifier component to provide a source identifier when the cable is determined to be a power delivery cable. 
     In Example 15 the subject matter of Example 14 can optionally include that the source identifier is an electronic signature. 
     In Example 16 the subject matter of Example 14 can optionally include that the source identifier to be provided over D+/D− pins of the cable. 
     In Example 17 the subject matter of Example 14 can optionally include that the source identifier to be provided over the cable between the electronic device and another electronic device. 
     In Example 18 the subject matter of Example 11 can optionally include that the logic includes a controller to change the output current limit of the electronic device. 
     In Example 19 the subject matter of Example 11 can optionally include that the electronic device is a power source device. 
     In Example 20 the subject matter of Example 11 can optionally include that the port is a universal serial bus (USB) port. 
     Example 21 is an electronic device to change an input current limit, comprising: a port to receive a plug of a cable, means for detecting the plug to couple to the port, means for determine an identification of a power source, and means for changing an input current limit of the electronic device based on the determined identification. 
     In Example 22 the subject matter of Example 21 can optionally include that the means for determining to determine the cable is a power delivery cable based on an electronic marking of the cable. 
     In Example 23 the subject matter of Example 22 can optionally include that the means for determining to determine a source identifier when the cable is determined to be a power delivery cable. 
     In Example 24 the subject matter of Example 22 can optionally include that the source identifier to be determined based an electronic signature. 
     In Example 25 the subject matter of Example 23 can optionally include that the source identifier to be provided on D+/D− pins of the cable. 
     In Example 26 the subject matter of Example 23 can optionally include that the source identifier to be provided over the cable between the power source and the electronic device. 
     In Example 27 the subject matter of Example 21 can optionally include that the means for changing includes a controller to change the input current limit of the electronic device. 
     In Example 28 the subject matter of Example 21 can optionally include that the electronic device to receive power at a current limit less than the input current limit. 
     In Example 29 the subject matter of Example 21 can optionally include that the port is a universal serial bus (USB) port. 
     Example 30 is an electronic device to change an output current limit, comprising: a port to receive a plug of a cable, means for detecting the plug to couple to the port, means for providing an identification of the electronic device, and means for changing an output current limit of the electronic device, and for providing power at a current level up to the output current limit. 
     In Example 31 the subject matter of Example 30 can optionally include that the means for detecting to determine the cable is a power delivery cable based on an electronic marking of the cable. 
     In Example 32 the subject matter of Example 31 can optionally include that the means for providing to provide a source identifier when the cable is determined to be a power delivery cable. 
     In Example 33 the subject matter of Example 32 can optionally include that the source identifier is an electronic signature. 
     In Example 34 the subject matter of Example 32 can optionally include that the source identifier to be provided over D+/D− pins of the cable. 
     In Example 35 the subject matter of Example 32 can optionally include that the source identifier to be provided over the cable between the electronic device and another electronic device. 
     In Example 36 the subject matter of Example 30 can optionally include that the means for changing includes a controller to change the output current limit of the electronic device. 
     In Example 37 the subject matter of Example 30 can optionally include that the electronic device is a power source device. 
     In Example 38 the subject matter of Example 30 can optionally include that the port is a universal serial bus (USB) port. 
     Example 39 is a method of changing an input current limit, comprising: detecting a plug to couple to a port of an electronic device, determining an identification of a power source, and changing an input current limit of the electronic device based on the determined identification. 
     In Example 40 the subject matter of Example 39 can optionally include that detecting the plug to include determining that a cable is a power delivery cable based on an electronic marking. 
     In Example 41 the subject matter of Example 40 can optionally include that the electronic marking is based on characteristics of an identification pin and a ground pin of the power delivery cable. 
     In Example 42 the subject matter of Example 40 can optionally include that determining the identification to include determining a source identifier when the cable is determined to be a power delivery cable. 
     In Example 43 the subject matter of Example 42 can optionally include that the source identifier to be determined based an electronic signature. 
     In Example 44 the subject matter of Example 42 can optionally include that the source identifier to be provided on D+/D− pins of the cable. 
     Example 45 is a method of changing an output current limit, comprising: detecting a plug to couple to a port of an electronic device, providing an identification of the electronic device, changing an output current limit of the electronic device, and providing power at a current limit less than the output current limit. 
     In Example 46 the subject matter of Example 45 can optionally include that detecting the plug to include determining that a cable is a power delivery cable based on an electronic marking of the cable. 
     In Example 47 the subject matter of Example 46 can optionally include that the electronic marking is based on characteristics of power detect pins of the power delivery cable. 
     In Example 48 the subject matter of Example 46 can optionally include that providing the identification to include providing a source identifier when the cable is determined to be a power delivery cable. 
     In Example 49 the subject matter of Example 48 can optionally include that the source identifier is an electronic signature. 
     In Example 50 the subject matter of Example 48 can optionally include that the source identifier to be provided over D+/D− pins of the cable. 
     In Example 51 the subject matter of Example 48 can optionally include that the source identifier to be provided over the cable between the electronic device and another electronic. 
     Example 52 is a computer-readable medium comprising one or more instructions that when executed on a processor to configure the processor to perform one or more operations to: detect a plug to couple to a port of an electronic device, determine an identification of a power source, and change an input current limit of the electronic device based on the determined identification. 
     In Example 53 the subject matter of Example 52 can optionally include that to detect the plug to include determining that a cable is a power delivery cable based on an electronic marking. 
     In Example 54 the subject matter of Example 53 can optionally include that the electronic marking is based on characteristics of an identification pin and a ground pin of the power delivery cable. 
     In Example 55 the subject matter of Example 53 can optionally include that to determine the identification to include determining a source identifier when the cable is determined to be a power delivery cable. 
     In Example 56 the subject matter of Example 55 can optionally include that the source identifier to be determined based an electronic signature. 
     In Example 57 the subject matter of Example 55 can optionally include that the source identifier to be provided on D+/D− pins of the cable. 
     Example 58 is a computer-readable medium comprising one or more instructions that when executed on a processor to configure the processor to perform one or more operations to: detect a plug to couple to a port of an electronic device, provide an identification of the electronic device, change an output current limit of the electronic device, and provide power at a current limit less than the output current limit. 
     In Example 59 the subject matter of Example 58 can optionally include that to detect the plug to include determining that a cable is a power delivery cable based on an electronic marking of the cable. 
     In Example 60 the subject matter of Example 59 can optionally include that the electronic marking is based on characteristics of power detect pins of the power delivery cable. 
     In Example 61 the subject matter of Example 58 can optionally include that to provide the identification to include providing a source identifier when the cable is determined to be a power delivery cable. 
     In Example 62 the subject matter of Example 61 can optionally include that the source identifier is an electronic signature. 
     In Example 63 the subject matter of Example 61 can optionally include that the source identifier to be provided over D+/D− pins of the cable. 
     In Example 64 the subject matter of Example 61 can optionally include that the source identifier to be provided over the cable between the electronic device and another electronic. 
     Any reference in this specification to “one embodiment,” “an embodiment,” “example embodiment,” etc., means that a particular feature, structure, or characteristic described in connection with the embodiment is included in at least one embodiment. The appearances of such phrases in various places in the specification are not necessarily all referring to the same embodiment. Further, when a particular feature, structure, or characteristic is described in connection with any embodiment, it is submitted that it is within the purview of one skilled in the art to affect such feature, structure, or characteristic in connection with other ones of the embodiments. 
     Although embodiments have been described with reference to a number of illustrative embodiments thereof, it should be understood that numerous other modifications and embodiments can be devised by those skilled in the art that will fall within the spirit and scope of the principles of this disclosure. More particularly, various variations and modifications are possible in the component parts and/or arrangements of the subject combination arrangement within the scope of the disclosure, the drawings and the appended claims. In addition to variations and modifications in the component parts and/or arrangements, alternative uses will also be apparent to those skilled in the art.