Abstract:
Circuits, methods, and apparatus where a dongle or adapter may provide continuous power in the event of a disconnection of a charging device. One example may provide a dongle having a charge storage circuit. A charging device connected to the dongle may be used to power an accessory also connected to the dongle. Following a disconnection of the charging device, the dongle may use the charger storage circuit to provide power to the accessory for a first duration. After the first duration, a host device also connected to the dongle may provide power to the accessory via the dongle.

Description:
CROSS-REFERENCES TO RELATED APPLICATIONS 
       [0001]    This application claims the benefit of U.S. provisional patent application No. 62/129,797, filed Mar. 7, 2015, which is incorporated by reference. 
     
    
     BACKGROUND 
       [0002]    The types of electronic devices that are commercially available has increased tremendously the past few years and the rate of introduction of new devices shows no signs of abating. Electronic devices, such as tablet, laptop, netbook, desktop, and all-in-one computers, cell, smart, and media phones, storage devices, portable media players, navigation systems, monitors, and others, have become ubiquitous. 
         [0003]    The amount of data transferred among these electronic devices has also grown. Large amounts of audio, streaming video, text, and other types of data content are now regularly transferred from one device to another. Power may be transferred with this data, though power may be transferred separately. Power and data may be conveyed over cables that may include wire conductors, fiber optic cables, or some combination of these or other conductors. Cable assemblies may include a connector insert at each end of a cable. The connector inserts may be inserted into connector receptacles in the communicating electronic devices to form pathways for power and data. 
         [0004]    In some circumstances, a user may want to connect a device having a first type of receptacle to a cable having a plug that is designed to mate with a second type of receptacle. To do this , the user may need an adapter to form a communication path. An adapter may have a receptacle of the second type to accept the cable and a plug of the first type to mate with the user&#39;s device. These adapters may include more than one type of receptacle. A convenient form factor for such a device may be referred to as a dongle. 
         [0005]    These dongles may be useful in that they may allow different types of devices to connect to a host using a single receptacle on the host. But a user may connect or disconnect these devices to and from the dongle from time to time. Various problems may arise as these connections and disconnections occur. 
         [0006]    Thus, what is needed are circuits, methods, and apparatus to counteract one or more of the various issues that may arise when a user connects or disconnects a device through such a dongle or adapter to a host. 
       SUMMARY 
       [0007]    Accordingly, embodiments of the present invention may provide circuits, methods, and apparatus to counteract one or more of the various issues that may arise when a user connects or disconnects devices through a dongle or adapter to a host or other device. An illustrative embodiment of the present invention may address a circumstance where a charger providing power to an accessory is disconnected from the dongle. Embodiments of the present invention may provide circuits, methods, and apparatus where a dongle or adapter may provide continuous power to an accessory in the event of a disconnection of the charging device. 
         [0008]    An illustrative embodiment of the present invention may provide a dongle having a charge storage circuit. A charging device connected to the dongle may be used to power an accessory also connected to the dongle. Following a disconnection of the charging device, the dongle may use the charger storage circuit to provide power to the accessory for a first duration. The dongle may also signal a host device connected to the dongle that the charger has been disconnected. After the first duration, the host device may provide power to the accessory via the dongle. This arrangement may be used to provide continuous power to the accessory in the event of a disconnection of the charger. 
         [0009]    Various dongles provided by embodiments of the present invention may have different form factors. An illustrative embodiment of the present invention may provide a dongle having a plug to mate with a host device. The plug may be connected to a housing by a cable. The housing may include one or more various receptacles. In an illustrative embodiment of the present invention, the plug may be a Universal Serial Bus type C (USB-C) plug compatible with a USB-C receptacle, though other types of plugs may be used. The receptacles on the housing may include one or more USB-C and other USB receptacles, receptacles for video connections, and other types of receptacles. One or more USB-C receptacles may be simplified receptacles intended to support power charging but not data communications. 
         [0010]    Various dongles provided by embodiments of the present invention may have different circuit configurations. An illustrative embodiment of the present invention may provide a dongle having a plug to connect to a host device and a first receptacle to connect to a charger. A power supply terminal on the plug may connect to a power supply terminal on the first receptacle. This power supply line may connect to a first terminal of a first switch. A second terminal of the first switch may connect to a first regulator. The first regulator may have an output coupled to a power supply terminal of a second receptacle, where the power supply terminal of a second receptacle may provide power to an accessory. The output of the first regulator may further couple to an input of a charge storage circuit. An output of the charge storage circuit may couple to a first terminal of a second switch. A second terminal of the second switch may couple to the second terminal of the first switch and the input of the first regulator. In this configuration, when power is received at the first receptacle from a charger, the first switch may be closed. This may allow the regulator to receive power from the power supply terminal of the first receptacle. The regulator may then provide power to an accessory over a power supply terminal of the second receptacle. The regulator may also charge the charge storage circuit. Following a disconnect of the charger, the first switch may open and the second switch may close, thereby allowing the charge storage circuit to provide power to the first regulator, such that the first regulator may continue to power to an accessory over a power supply terminal of the second receptacle. After a first duration, the host may be ready to provide power to the power supply terminal in the plug. Accordingly, the first switch may close to connect the power supply terminal in the plug to the first regulator, such that the first regulator may continue to power to an accessory over a power supply terminal of the second receptacle. The second switch may open to disconnect the charge storage circuit, thereby protecting power supply circuitry in the host device. 
         [0011]    Embodiments of the present invention may employ various types of charge storage circuits. An illustrative embodiment of the present invention may provide a charge storage circuit that includes a second power supply regulator driving one or more capacitors. To increase the stored charge, the voltage provided by the second regulator may be increased, for example with a buck-boost or other type of boost regulator. 
         [0012]    Embodiments of the present invention may employ various signaling schemes to communicate between a host device and a dongle or adapter. An illustrative embodiment of the present invention may provide a host and a dongle that are able to communicate and inform each other that they are capable of performing a quick power supply changeover in the event of a power supply charger disconnection. This communication may also include a negotiation for an amount of power to be provided by the host to the dongle in the event of a power supply charger disconnection, though these negotiations may occur following a power supply charger disconnection. These negotiations may be simply implied by the fact that the host and dongle may each be capable of performing a quick power supply changeover technique according to an embodiment of the present invention in the event of a power supply charger disconnection. Since the host is capable of performing a quick power supply changeover, it may arm an internal power supply regulator such that it may be used to quickly provide power in the event of a power supply charger disconnection. Following a disconnection, the dongle may signal the host that the disconnection has occurred using a bidirectional signal line. The dongle may then power an accessory using charge in its charge storage circuit. After a first duration, the host device may then signal the dongle that the host is ready to provide power. The host may do this by signaling the dongle using the same bidirectional signal line. The dongle may then transition from using power in its charge storage circuit to using power supplied by the host. Again, if needed, the host and dongle may negotiate for an amount of power to be provided by the host to the dongle now that the power supply charger has been disconnected. 
         [0013]    Embodiments of the present invention may provide dongles or adapters that may be connected to or between various types of devices, such as portable computing devices, tablet computers, desktop computers, laptops, all-in-one computers, wearable computing devices, cell phones, smart phones, media phones, storage devices, portable media players, navigation systems, monitors, power supplies, adapters, remote control devices, chargers, and other devices. 
         [0014]    These dongles or adapters may include plugs and receptacles that provide pathways for signals that are compliant with various standards such as USB including USB-C, High-Definition Multimedia Interface® (HDMI), Digital Visual Interface (DVI), Video Graphics Array (VGA), Ethernet, DisplayPort, Thunderbolt™, Lightning™, Joint Test Action Group (JTAG), test-access-port (TAP), Directed Automated Random Testing (DART), universal asynchronous receiver/transmitters (UARTs), clock signals, power signals, and other types of standard, non-standard, and proprietary interfaces and combinations thereof that have been developed, are being developed, or will be developed in the future. Other embodiments of the present invention may provide connector receptacles and inserts or plugs that may be used to provide a reduced set of functions for one or more of these standards. In various embodiments of the present invention, these interconnect paths provided by these connector receptacles and inserts or plugs may be used to convey power, ground, signals, test points, and other voltage, current, data, or other information. 
         [0015]    In various embodiments of the present invention, contacts and other conductive portions of these dongles or adapters may be formed by plating, depositing, stamping, metal-injection molding, machining, micro-machining, 3-D printing, or other manufacturing process. The conductive portions may be formed of stainless steel, steel, copper, copper titanium, phosphor bronze, gold, or other material or combination of materials. They may be plated or coated with nickel, gold, or other material. The nonconductive portions, such as the housings cable insulation, may be formed using injection or other molding, 3-D printing, machining, or other manufacturing process. The nonconductive portions may be formed of silicon or silicone, rubber, hard rubber, plastic, nylon, liquid-crystal polymers (LCPs), or other nonconductive material or combination of materials. 
         [0016]    Various embodiments of the present invention may incorporate one or more of these and the other features described herein. A better understanding of the nature and advantages of the present invention may be gained by reference to the following detailed description and the accompanying drawings. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0017]      FIG. 1  illustrates a portion of an electronic system according to an embodiment of the present invention; 
           [0018]      FIGS. 2A-2C  illustrate a method of providing power through a dongle according to an embodiment of the present invention; 
           [0019]      FIGS. 3A-3C  illustrates the operation of a dongle circuit according to an embodiment of the present invention; 
           [0020]      FIGS. 4A -4F  illustrates a method of signaling between devices according to an embodiment of the present invention; 
           [0021]      FIG. 5  is a schematic for switch S 1  according to an embodiment of the present invention; 
           [0022]      FIG. 6  illustrates control circuitry for opening and closing switch S 1  according to an embodiment of the present invention; 
           [0023]      FIG. 7  is a schematic for switch S 2  according to an embodiment of the present invention; 
           [0024]      FIG. 8  is a schematic for a charge storage circuit according to an embodiment of the present invention; 
           [0025]      FIG. 9  illustrates a circuit for a dongle according to an embodiment of the present invention; and 
           [0026]      FIG. 10  is a timing diagram illustrating an operation of an electronic system according to an embodiment of the present invention. 
       
    
    
     DESCRIPTION OF EXEMPLARY EMBODIMENTS 
       [0027]      FIG. 1  illustrates a portion of an electronic system according to an embodiment of the present invention. This figure, as with the other included figures, is shown for illustrative purposes and does not limit either the possible embodiments of the present invention or the claims. 
         [0028]    This figure includes a host device  110  connected to a dongle or adapter  120 . Host device  110  may be a portable computing device, tablet computer, desktop computer, laptop, all-in-one computer, wearable computing device, cell phone, smart phone, media phone, storage device, portable media player, navigation system, monitor, power supply, adapter, remote control device, or other device. Host device  110  may include a receptacle  112 . Receptacle  112  may be a USB-C or other type of receptacle. 
         [0029]    Dongle  120  may include a plug  122  that may be connected to a housing  125  through a cable  124 . Plug  122  may be configured to mate with receptacle  112 . Plug  122  may be a USB C or other type of plug. Housing  125  may include one or more receptacles  126 ,  127 , and  128  for receiving connections to other devices, which are not shown for simplicity. Plug  122  and receptacles  126 ,  127 , and  128 , may be various types of plugs and receptacles such as USB-C, HDMI, DVI, VGA, Ethernet, DisplayPort, Thunderbolt, Lightning, JTAG, TAP, DART, UART, clock signals, power signals, and other types of standard, non-standard, and proprietary interfaces and combinations thereof that have been developed, are being developed, or will be developed in the future. These and other embodiments of the present invention may provide connector receptacles and inserts or plugs that may be used to provide a reduced set of functions for one or more of these standards. 
         [0030]    In a specific embodiment of the present invention, one of these receptacles may be a USB-C receptacle. This USB-C receptacle may be modified or simplified to accept a plug connected to a charger. For example, receptacle  126  may be a simplified USB-C receptacle that may receive power but may not useful for data transfers. Receptacle  127  may be a video or other type of receptacle, such as an HDMI, DVI, DisplayPort, VGA, Thunderbolt, or other type of receptacle. 
         [0031]    Another receptacle, for example receptacle  128 , may be a USB-A type receptacle. This USB-A type receptacle may be used to receive a connection from an accessory, such as a mass storage unit or other type of accessory. 
         [0032]    Accordingly, the electronic system shown in this figure may be connected to a charger via receptacle  126 , and a mass storage unit, such as a hard disk drive, via receptacle  128 . In this configuration, power from the charger received at receptacle  126  may be provided to the mass storage unit via receptacle  128  and to the host device  110  via plug  122 . 
         [0033]    An issue may arise when the charger connection is removed from receptacle  126 . Specifically, the source of power for an accessory connected to receptacle  128  may be removed. If this accessory does not have its own power source, power may be removed from the accessory and the accessory may cease functioning. This may be particularly troublesome if a charger is removed from receptacle  126  while a data transfer is taking place between host device  110  and a mass storage unit connected to receptacle  128 . This may lead to a loss of data, which may lead to user dissatisfaction. 
         [0034]    Accordingly, embodiments of the present invention may provide a dongle  120  that is capable of providing power to an accessory coupled to receptacle  128  following a disconnect of a charger at receptacle  126 . Dongle  120  may provide power for a short duration until host device  110  is able to provide power via plug  124  to the accessory connected to receptacle  128 . An example of this is shown in the following figures. 
         [0035]      FIGS. 2A-2C  illustrate a method of providing power through a dongle according to an embodiment of the present invention. In  FIG. 2A , charger  210  may provide power to dongle  120  and via lines  212 . Dongle  120  may in turn provide the charger power to host or device  110  over lines  232  and to accessory  220  over lines  222 . Control signals on lines  234  may be inactive at this time. 
         [0036]    In  FIG. 2B , charger  210  may be disconnected from dongle  120 . This disconnection may result when a user extracts a plug connected to charger  210  from receptacle  128 . This disconnection may occur inadvertently, for example during a power failure, or when someone trips over cable attached to the charger. A disconnection may also occur when power is removed from the charger  210 . At this time, charger  210  is not able to provide power to accessory  220 . Also, host device  110  may not react quickly enough to provide power to avoid a power down of accessory  220 . Accordingly, embodiments of the present invention may provide a charge storage circuit in dongle  120 . This charge storage circuit may provide power to accessory  220  for the period of time after charger  210  is disconnected until host device  110  may provide power to accessory  220 . Following the disconnection of charger  210 , dongle  120  may alert host device  110  that the charger  210  has been disconnected. This may inform host  110  that it needs to provide power to dongle  120 . 
         [0037]    In  FIG. 2C , power is provided by host device  110  on lines  232  to dongle  120 . This power may in turn be provided by dongle  120  to accessory  220  over lines  222 . This configuration may provide a seamless transition of power from charger  210  to host or device  110 , where for a short transition of power is provided by the charge storage circuit in dongle  120 . 
         [0038]    Various embodiments of the present invention may employ various types of circuitry in dongle  120 . An example is shown in the following figure. 
         [0039]      FIGS. 3A-3C  illustrates the operation of a dongle circuit according to an embodiment of the present invention. In  FIG. 3A , power may be received from a charger at USB-C receptacle  126  and provided to a host device through USB-C plug  122 , and to an accessory via 
         [0040]    USB-A receptacle  128 . USB-C plug  122  may have a power supply terminal that is connected on line V 1  to a power supply terminal in USB-C receptacle  126 . These power supply terminals may be bi-directional power supply terminals. Line V 1  may be connected to switch S 1 . In this configuration, S 1  may be closed allowing power on line V 1  to drive regulator  320  via line V 2 . Regulator  320  may provide power on line V 3  to a power supply terminal in USB-A receptacle  128 . This power may then be delivered to accessory (not shown.) Regulator  320  may also provide power to charge storage circuit  330 . Charge storage circuit  330  may be charged so that is ready when needed following a disconnection or other cessation of reception of power from the charger. The output of charge storage circuitry  330  on line V 4  may be isolated by switch S 2 , which may be open at this time. Regulator  320  may be a buck-boost regulator or other type of regulator. 
         [0041]    In  FIG. 3B , the charger is disconnected from USB-C receptacle  126 . Again, this disconnection may be a physical disconnection, or it may be that power has been removed from the charger. At this time, power is no longer available from the charger, and power is not yet available from the host device to power the accessory connected to USB-A receptacle  120 . 
         [0042]    Accordingly, switch S 1  may open and switch S 2  may close. This may connect the output of charge storage circuitry  320  to regulator  320  over line V 2 . Regulator  320  may then provide power on line V 3  to USB-A receptacle  128 , and thus to the accessory. 
         [0043]    In  FIG. 3C , power may be received from a host device via USB-C plug  122 . At this time, the charge storage circuit  330  may be disconnected. Specifically, switch S 1  may close allowing power from the host device to reach regulator  320  via a USB-C plug  122 . Switch S 2  may open thereby disconnecting charge storage circuit  330 . As before, regulator  320  may provide power to USB-A receptacle  128 , and thereby to the accessory. 
         [0044]    Various types of signaling may be used in electronic systems according to embodiments of the present invention. An example is shown in the following figures. 
         [0045]      FIGS. 4A-4F  illustrates a method of signaling between devices according to an embodiment of the present invention. In  FIG. 4A , dongle  120  is connected to host device  110 . Dongle  120  is further connected to receive power from charger  210  and to provide power to accessory  220 . Specifically, charger  210  may provide power to dongle  120  over lines  212 . Dongle  120  may further provide this power to host device  110  over lines  232  and to accessory  220  over lines  222 . During this initial setup, the host in dongle may determine using one or more control lines  234  that they are each capable of supporting a quick power swap technique provided by an embodiment of the present invention. At this time, the devices may further negotiate for a level of power that host  110  would provide to dongle  120  in the event of a disconnection by charger  210 . In other embodiments of the present invention, these further negotiations may be delayed until host device  110  actually needs to provide power to dongle  120 . In still other embodiments the present invention, a level of power that a host device  110  may provide to dongle  120  may be implied by the fact that they are both capable of supporting a quick power swap technique provided by an embodiment of the present invention. In various embodiments of the present invention, different signals may be used for these negotiations. For example, where a host device  110  and dongle  120  are connected using a USB-C interface, low speed data signal lines D 2 N and D 2 P may be used. These signal lines may be used to convey what may be referred to as an SOS signal and a presence signal respectively. The SOS signal may be used by dongle  120  to inform the host that the host needs to provide quickly, hence the name. The presence signal may indicate that dongle  120  is connected to host  110 . 
         [0046]    In  FIG. 4B , host device  110  may turn on a regulator that may supply power, though this regulator may not be needed at this time, or may only be needed for limited purpose. Also at this time, dongle  120  may charge its charge storage circuit. 
         [0047]    In  FIG. 4C  charger  210  may be disconnected from dongle  120 . Again, this may be a physical disconnection, or it may be that power has been removed from charger  210 . At this time, power is not available from charger  210 , and host or device  110  has not yet connected its regulator to dongle  120 . Accordingly, power may be provided by the charge storage circuit in dongle  120  over lines  222  to accessory  220 . At this time, dongle  120  may signal an SOS over lines  234  to host device  110 . This SOS signal may be a high signal on line DP 2 . 
         [0048]    In  FIG. 4D , power may be provided by host device  110  to dongle  120  over lines  232 . Host device  110  may pull the SOS signal low to indicate that power may be drawn by the dongle  120 . Dongle  120  may then transition from providing power from the charge storage circuit to providing power from the host device  110  over lines  222  to accessory  220 . 
         [0049]    In  FIG. 4E , dongle  120  may provide power from the host device  110  over lines  222  to accessory  220 . 
         [0050]    In  FIG. 4F , host device  110  may release the SOS signal allowing it to return high. As described above, if they have not done so already, host  110  and dongle  120  may negotiate for a power level to be provided by host  110  to dongle  120 . 
         [0051]    Again, circuitry in dongle  120  may be implemented in a number of ways. An example is shown in the following figures. 
         [0052]      FIG. 5  is a schematic for switch S 1  according to an embodiment of the present invention. Switch S 1  may be formed by 2 p-channel transistors MP 1  and MP 2  connected in series. A high signal received on line S 1  ON may close switch S 1 . Specifically, transistor MN 1  may turn on providing a voltage at the gate of transistor MP 1 , thereby turning transistor MP 1  on. Transistor MN 1  may receive and enable signal. When the enable signal is high, transistor MN 2  may turn on, thereby providing a voltage the gate of transistor MP 2  turning it on, thereby closing switch S 1  and completing the connection between terminals V 1  and V 2 . 
         [0053]      FIG. 6  illustrates control circuitry for opening and closing switch S 1  according to an embodiment of the present invention. Comparator C 1  may compare a portion of a voltage received via charger on line V 1  to a threshold voltage. When the portion of the received voltage drops below the threshold voltage, the output of comparator C 1  may go low, thereby shutting off or opening switch S 1 . When the portion of a voltage received via charger on line V 1  is higher than the threshold voltage, switch S 1  may be on or closed. 
         [0054]    In various embodiments of the present invention, it may be a desirable to open switch S 1  when a voltage on line V 2  is higher than a voltage on line V 1 . Preventing switch S 1  from closing at this time may provide protection by preventing switch S 1  from connecting a high voltage at the output of the charge storage circuit through switch S 2  and back into the host device regulator. Accordingly, comparator C 2  may be included. Comparator C 2  may compare the voltage on line V 1  to the voltage on line V 2  (or more specifically, portions of these voltages), and when the voltage on line V 1  is lower than the voltage on V 2 , the output of comparator C 2  may be low, again turning off or opening switch S 1 . Capacitor C 2  may be included at the positive terminal of comparator C 2  to slow the reaction time of the positive input. This may be particularly useful when S 1  is on and V 1  and V 2  are close to the same voltage. If at this time S 2  is closed, both inputs to comparator C 2  could rise at the same rate and comparator C 2  may not properly drive output S 1  ON low thereby opening switch S 1 . By slowing the voltage response at the positive input to comparator C 2 , a high voltage appearing on V 2  may immediately drive the output S 1  ON of comparator C 2  low, thereby turning off switch S 1 . In normal operation comparator C 1  may have already turned off and opening switch S 1  before turning on and closing switch S 2 , in which case this extra protection may not be activated. In this way, the capacitor C 2  may ensure that S 1  is not turned on and closed until V 2  drops below V 1 , at which time the host may begin providing power after a power role swap. 
         [0055]      FIG. 7  is a schematic for switch S 2  according to an embodiment of the present invention. As shown in  FIGS. 3A-3C , when switch S 1  is closed, switch S 2  is open, and when S 1  is open, S 2  is closed. Accordingly, switch S 2  may be driven by an inversion of the S 1  ON signal. This inversion may be provided by logic inverter G 1 . When S 1  is closed, signal S 1  ON is high, and the output of G 1  is low. This signal is received at the base of transistor N 1  and the collector of N 1  may then rise to V 2 . With no current flow through the resistor R 3 , transistors MP 3  and MP 4  may be off and switch S 2  may be open. When switch S 1  is open, the signal S 1  ON may be low and the output of inverter G 1  may be high. This may turn transistor N 1  on providing a voltage across resistor R 3 . This may turn on transistors MP 3  and MP 4 , thereby closing switch S 1  between lines V 2  and V 4 . 
         [0056]    A capacitors C 3  may be included across resistor R 3  to slow response times of switch S 2 . A resistor R 4  may be included across transistor MP 4 . This resistor R 4  may be used to limit current provided through regulator  320  when it is initially providing charge to the charge storage circuitry  130 . 
         [0057]      FIG. 8  is a schematic for a charge storage circuit according to an embodiment of the present invention. This charge storage circuit may receive power on line V 3  from regulator  320 . Regular  810  may boost this voltage to a higher voltage in order to increase the total charge stored on one or more capacitors connected at its output. In this example, three capacitors C 4 , C 5 , and C 6  are shown, though in other embodiments of the present invention, one, two, or more than three capacitors may be coupled at the output of regulator  810 . 
         [0058]      FIG. 9  illustrates a circuit for a dongle according to an embodiment of the present invention. In this example, the previous schematics for switches S 1  and S 2 , control circuitry for switch S 1 , and circuitry for the charge storage circuit are included. Additional transistors MN 3  and MN 4  are included. Transistors MN 3  and MN 4  may be shut off to disconnect connections to the plug  122  and receptacle  126 . 
         [0059]      FIG. 10  is a timing diagram illustrating an operation of an electronic system according to an embodiment of the present invention. Initially, power delivery communications may be conducted at stage  1010 . At this time, a host device and dongle may determine that each are capable of carrying out their role in a quick power swap technique according to an embodiment of the present invention. At stage  1020 , a host device may enable a regulator that may be used to provide power in the event of a charger disconnection. A power adapter or charger may be unplugged from the dongle, as shown by the adapter unplug event. The dongle may signal to the host that such a disconnection has occurred at the start of state  1032 . During this time, the host may begin to prepare to provide power to the dongle, and the dongle may provide power using a charge storage circuit. At  1034 , the host device may pull down on the SOS line indicating the dongle may use power supplied by the host. The host may provide power at stage  1042 . At stage  1012 , if necessary, the host and dongle may negotiate for a power level to be provided by the host to the dongle. 
         [0060]    Embodiments of the present invention may provide dongles or adapters that may be connected to or between various types of devices, such as portable computing devices, tablet computers, desktop computers, laptops, all-in-one computers, wearable computing devices, cell phones, smart phones, media phones, storage devices, portable media players, navigation systems, monitors, power supplies, adapters, remote control devices, chargers, and other devices. 
         [0061]    These dongles or adapters may include plugs and receptacles that provide pathways for signals that are compliant with various standards such as Universal Serial Bus (USB) including USB-C, High-Definition Multimedia Interface® (HDMI), Digital Visual Interface (DVI), Ethernet, DisplayPort, VGA, Thunderbolt™, Lightning™, Joint Test Action Group (JTAG), test-access-port (TAP), Directed Automated Random Testing (DART), universal asynchronous receiver/transmitters (UARTs), clock signals, power signals, and other types of standard, non-standard, and proprietary interfaces and combinations thereof that have been developed, are being developed, or will be developed in the future. Other embodiments of the present invention may provide connector receptacles and inserts or plugs that may be used to provide a reduced set of functions for one or more of these standards. In various embodiments of the present invention, these interconnect paths provided by these connector receptacles and inserts or plugs may be used to convey power, ground, signals, test points, and other voltage, current, data, or other information. 
         [0062]    In various embodiments of the present invention, contacts and other conductive portions of these dongles or adapters may be formed by plating, depositing, stamping, metal-injection molding, machining, micro-machining, 3-D printing, or other manufacturing process. The conductive portions may be formed of stainless steel, steel, copper, copper titanium, phosphor bronze, gold, or other material or combination of materials. They may be plated or coated with nickel, gold, or other material. The nonconductive portions, such as the housings cable insulation, may be formed using injection or other molding, 3-D printing, machining, or other manufacturing process. The nonconductive portions may be formed of silicon or silicone, rubber, hard rubber, plastic, nylon, liquid-crystal polymers (LCPs), or other nonconductive material or combination of materials. 
         [0063]    The above description of embodiments of the invention has been presented for the purposes of illustration and description. It is not intended to be exhaustive or to limit the invention to the precise form described, and many modifications and variations are possible in light of the teaching above. The embodiments were chosen and described in order to best explain the principles of the invention and its practical applications to thereby enable others skilled in the art to best utilize the invention in various embodiments and with various modifications as are suited to the particular use contemplated. Thus, it will be appreciated that the invention is intended to cover all modifications and equivalents within the scope of the following claims.