Patent Publication Number: US-8984188-B2

Title: External contact connector

Description:
CROSS-REFERENCES TO RELATED APPLICATIONS 
     This application is a continuation of International Application No. PCT/US2012/022795 filed Jan. 26, 2012, which claims benefit of U.S. Provisional Patent Application No. 61/436,545 filed on Jan. 26, 2011. The contents of both these applications are incorporated by reference herein in their entirety for all purposes. 
    
    
     FIELD OF INVENTION 
     The present invention relates generally to input/output electrical connectors such as audio connectors and data connectors and in particular to slim or low profile connectors that can be used in place of standard connectors currently used. 
     BACKGROUND 
     There are many different types of connectors available in the market for connecting a host device and an accessory. Most connectors are manufactured to perform a specific function. Moreover, each contact in a conventional connector is designated to carry a particular signal, e.g., power, audio data, video data, etc. The manufacturer of the host device and/or the accessory generally defines the function of each contact within a connector. Once a conventional connector is designed and manufactured based on the specifications, the contacts cannot be configured on the fly during operation. For example, in a USB connector, certain contacts are designated for carrying data. These contacts cannot be reconfigured dynamically to carry any other signals. In other words, the data contacts in a USB connector can only carry data signals and not any other signals. 
     SUMMARY 
     Embodiments of the present invention provides a receptacle connector in which individual contacts are dynamically configurable based on the desired function for each contact. Additionally, plug connectors according to the present invention have external contacts instead of internal contacts and thus do not include a cavity that is prone to collecting and trapping debris. Other embodiments of the invention pertain to receptacle connectors adapted to mate with plug connectors of the invention. 
     To better understand the nature and advantages of the present invention, reference should be made to the following description and the accompanying figures. It is to be understood, however, that each of the figures is provided for the purpose of illustration only and is not intended as a definition of the limits of the scope of the present invention. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1A  is a simplified perspective view of a connector plug according to an embodiment of the invention; 
         FIG. 1B  is a pin-out schematic for the connector plug according to an embodiment of the present invention; 
         FIG. 2A  is a simplified perspective view of a receptacle connector according to an embodiment of the present invention; 
         FIG. 2B  is a simplified cross-sectional schematic view of the receptacle connector according to an embodiment of the present invention; 
         FIG. 3  is a table illustrating the various signals that can be used with the plug connector and the receptacle connector according to an embodiment of the present invention; 
         FIG. 4  is a block diagram illustrating a host device communicably coupled to an accessory according to an embodiment of the present invention; 
         FIG. 5  is a block diagram illustrating a host device communicably coupled to an accessory device according to another embodiment of the present invention; 
         FIG. 6  is a block diagram illustrating a host device communicably coupled to an accessory device according to yet another embodiment of the present invention; and 
         FIGS. 7A-7C  is a flow diagram of a process for conducting communication between a host device and an accessory device according to an embodiment of the present invention. 
     
    
    
     DETAILED DESCRIPTION 
     In order to better appreciate and understand the present invention, reference is made to  FIG. 1A  which depicts a plug connector  100  according to the present invention. Specifically,  FIG. 1A  is a simplified perspective view of plug connector  100 . As shown, connector  100  includes a tab  102  that extends from an outer shell  108  that can be made from a dielectric material such as a thermoplastic polymer and formed in an injection molding process. Tab  102  has a front major surface upon which two contacts  104   a  and  104   b  are positioned and a back major surface (not shown) upon which two additional contacts  104   c  and  104   d  (not shown) are located. The contacts can be made from a copper, nickel, brass, a metal alloy or any other appropriate conductive material. Spacing is consistent between each of the contacts on the front and back sides and between the contacts and the edges of the connector providing  180  degree symmetry so that plug connector  100  can be inserted into a corresponding receptacle connector in either of two orientations as discussed below. 
     A significant portion of tab  102  is part of a ground ring  110  that extends from a distal tip of the connector towards the outer shell and partially surrounds contacts  104   a - 104   d  along an outer periphery of tab  102 . Ground ring  110  can be made from any appropriate metal or other conductive material and in one embodiment is stainless steel plated with copper and nickel. Two indentations or pockets  106   a  and  106   b  (not shown) are formed in ground ring  110  and located on opposing sides of tab  102  near its distal end. In operation, tab  102  is inserted into a receptacle connector (shown in  FIGS. 4 and 5 ) until pockets  106   a  and  106   b  operatively engage with a retention mechanism, such as a cantilevered spring or detent. The retention mechanism fits within pockets  106  and provides a retention force that secures connector  100  to the matching receptacle connector. In order for the connectors to be separated, a force greater than the retention force must be supplied in a direction that pulls the mated connectors away from each other. In other embodiments, other retention mechanisms can be used such as mechanical or magnetic latches or orthogonal insertion mechanisms. 
     As shown in  FIG. 1A , contacts  104   a - 104   d  are external contacts that are positioned along an outer surface of tab  102  and connector  100  does not include an exposed cavity in which particles and debris may collect. To improve robustness and reliability, connector  100  is fully sealed and includes no moving parts. Furthermore, connector  100  has a considerably reduced insertion depth and insertion width as compared to commonly available connectors. For example, in one embodiment, the width of the plug connector is about 40 mm or less, thickness is about 1.5 mm or less, and insertion depth is about 6 mm or less. It is understood that the dimensions of connector  100  as well as the number of contacts may vary in different embodiments. 
     When connector  100  is properly engaged with a receptacle connector each of contacts  104   a  and  104   b  is in electrical contact with a corresponding contact in the receptacle connector. Tab  100  has a  180  degree symmetrical, double orientation design which enables the connector to be inserted into a connector jack in both a first orientation or a second orientation. Thus, connector  50  can be said to be orientation agnostic. In the first orientation, plug connector contacts  104   a  and  104   b  couple to receptacle contacts. In the second orientation opposite the first orientation, plug contacts  104   c  and  104   d  couple to receptacle contacts. 
     In order to ensure that the receptacle connector&#39;s contacts properly align with the plug connector contacts in each orientation, a sensing circuit in the receptacle connector or the host device in which the receptacle connector is housed, can detect the orientation of the connector and set software and/or hardware switches to switch internal connections to the contacts in the receptacle connector and properly match the receptacle connector&#39;s contacts to the plug connector&#39;s contacts as appropriate. In some embodiments the orientation of the plug connector can be detected based on a physical key in the connector. In other embodiments, such as the embodiments represented by connector  100 , the plug connector does not include a physical key and the orientation is instead detected by circuitry associated with the corresponding receptacle connector based on signals received over the contacts. 
     As an example, various accessories such as headsets for cellular phones include a microphone and allow a user to perform basic functions such as setting earphone volume and answering and ending calls with the push of a button on the accessory. A single wire, serial control chip can be used to communicate with the host electronic device and implement this functionality over a particular contact or set of contacts. When the plug connector is inserted into the receptacle jack, the serial control chip can talk to appropriate circuitry in host electronic device via the designated contact or contacts. Upon an insertion event, the host device sends an Acknowledgment signal to the serial control chip over the designated contact in the receptacle connector and waits for a Response signal. If a Response signal is received, the receptacle connector contacts are aligned properly and audio and other signals can be transferred between the connectors. If no Response signal is received, the host device flips the contacts on the receptacle connector to correspond to the second possible orientation (i.e., flips the contacts 180 degrees) and repeats the Acknowledgement/Response signal routine. 
     In a specific embodiment, connector  100  is a highly serialized port that provides all video, audio, USB and other data signals over two pairs of serial contacts. Thus, connector  100  includes just four contacts: A first pair of differential transmit data contacts  104   a  and  104   b  on one side of the connector, and a second pair of differential receive data contacts  104   c ,  104   d  (not shown in  FIG. 1 ) on the opposite side. As discussed above, connector  100  is orientation agnostic and can be inserted into a corresponding receptacle connector in any one of two orientations.  FIG. 2  is a diagram depicting pin locations of connector plug  100  according to one embodiment of the invention. None of the four contacts are dedicated for power. Instead, power can be supplied over the data contacts using a standard such as power over Ethernet. 
       FIG. 1B  illustrates contact configuration of connector  100  according to an embodiment of the present invention. As illustrated in  FIG. 1B , contacts  104   a  and  104   b  may carry the differential data signals for the data that is being transmitted from plug connector  100  to a host device. Contacts  104   c  and  104   d  may carry the differential data signals for the date is being received from the host device. A receptacle connector associated with the host device may have complementary contacts that receive signals from and transmit signals to the accessory via plug connector  200 . 
       FIG. 2A  illustrates a receptacle connector  200  according to an embodiment of the present invention. Receptacle connector  200  includes a housing  202  that defines a cavity  204  and houses N contacts  206   (1) - 206   (N)  within the cavity. In operation, a connector plug, such as plug connector  100  can be inserted into cavity  204  to electrically couple the contacts  104   a ,  104   b  or  104   c ,  104   d  to respective contacts  206   (1) - 206   (N) . Each of the receptacle contacts  206   (1) - 206   (N)  electrically connects its respective plug contact to circuitry associated with the electrical device in which receptacle connector  200  is housed. For example, receptacle connector  200  can be part of a portable media device and electronic circuitry associated with the media device is electrically connected to receptacle  200  by soldering tips of contacts  206   (1) - 206   (N)  that extend outside housing  202  to a multilayer board such as a printed circuit board (PCB) within the portable media device. In some embodiments, connector  200  may have contacts on each side corresponding to the contacts on plug connector  100 . 
     In some embodiments, receptacle connector  200  may have four contacts  206   (1)-(N)  with two contacts  206   (3) - 206   (4)  arranged along a top side inside cavity  204  and two contacts  206   (1) - 206   (2)  arranged along a bottom side inside cavity  204  as illustrated in  FIG. 2B . Each of these contacts may be configured to perform one of several functions depending on the signals available on a plug connector. Plug connector  100  may be associated with any one of several accessories that may be designed to work with a host device that is associated with receptacle connector  200 . For example, plug connector  100  may be associated with an audio only accessory in which case the signals available on the contacts of the plug connector may include audio and related signals. In other instances, where plug connector  100  is associated with a more complex accessory such as video accessory, the contacts of plug connector may carry audio, video, and related signals. Thus, in order to enable receptacle connector  200  to be operable with various different types of signal, contacts  206   (1)-(4)  of receptacle connector  200  can be made dynamically configurable based on the signals available from a plug connector  100 . 
     In the particular embodiment illustrated in  FIG. 2B , receptacle connector  200  has four contacts  206   (1)-(4) . Each contact  206   (1)-(4)  has an associated multiplexing circuitry  220  that can configure the contact to carry on of many possible signals. In some embodiments, multiplexing circuitry may be a switch that can connect the associated contact to one of several signal paths. However, for ease of explanation only one multiplexing circuit  220  associated with contact  206   (2)  is illustrated in  FIG. 2B . It is to be noted that each of the contacts  206   (1) - 206   (4)  may have a multiplexing circuit coupled to it. In other embodiments, both the contacts may be coupled to a single multiplexing circuit that configures the contacts. As illustrated in  FIG. 2B , switch  220  can be used to configure contact  206   (2)  to carry any one of signals S 1 -S n  depending on the configuration of the plug connector. 
     For example, consider that plug connector  100  has contact configuration as illustrated in  FIG. 1B . When plug connector  100  is inserted into receptacle connector  200 , the four contacts of plug connector  100  are in physical contact with the four contacts of receptacle connector  200 . In order to receive/transmit data via plug connector  100 , the receptacle connector contacts have to be configured accordingly. In other words, the receptacle connector contacts that are in physical contact with contacts  104   a  and  104   b  of plug connector  100  have to be configured to receive data and the receptacle connector contacts that are in physical contact with contacts  104   c  and  104   d  of plug connector  100  have to be configured to transmit data. The switching circuit  220  can be used to couple the contacts in receptacle connector to appropriate circuitry in the host device. For instance, if contacts  104   a  and  104   b  are carrying an audio signal to the host device, the corresponding contacts in receptacle connector can be coupled to the circuitry that can receive and process the audio signal. 
       FIG. 3  is a table illustrating some sample configurations for the input/output signals that may be available on contacts  104   a - 104   d  of plug connector  100  according to an embodiment of the present invention. As illustrated in  FIG. 3 , if plug connector  100  is associated with a charge/sync cable, then contact  104   a  may carry the voltage (e.g., VBus), contact  104   b  may be unused (or floating), contacts  104   c  and  104   d  may be used for differential data signals. 
     In the instance where connector  100  is associated with a powered accessory, contact  104   a  may carry the voltage (e.g., VBus), contact  104   b  may carry the accessory ID signal, and contacts  104   c  and  104   d  may be used for differential data signals. 
     In the instance where connector  100  is associated with a wired headset accessory, or a headphone adapter, contact  104   a  may carry the microphone out signal, contact  104   b  may be used as analog ground, and contacts  104   c  and  104   d  may be used for left and right audio signals, respectively. 
     In the instance where connector  100  is associated with an unpowered accessory, contact  104   a  may carry the voltage out signal, contact  104   b  may be carry the accessory ID signal, and contacts  104   c  and  104   d  may be used for differential data signals, respectively. 
     In an embodiment, plug connector  100  may be associated with an audio/video adapter accessory. In this instance plug connector  100  may have four contacts with two contacts dedicated for receiving data and two contacts dedicated to transmitting data. Such a video adapter may support a variety of data types such as HDMI, VGA, component video, digital and/or analog audio, and other audio/video related signals. In this instance some or all of these various signals may need to be communicated between the host device and the accessory. In order to accomplish this using the available four contacts. The data is serialized and de-serialized on the host and/or the accessory side and transmitted at a very high rate, e.g., 10-15 Gbits/sec over the two transmit contacts and received at the same high rate via the two receive contacts. This enables even the bandwidth intensive data, e.g., hi-definition video data, to be transmitted and received using just two contacts. In an embodiment, the video data received/transmitted by the accessory may include display port related data. In some embodiments, the accessory can transmit/receive, audio, video and other data over the two receive and the two transmit contacts. In some embodiments, the other data may include control data, accessory identification data, host identification data, or any other non-audio or non-video data. 
     Based on the contact configuration of plug connector, the contacts of the receptacle connector can be configured to match that configuration. Thus, by using only four contacts in a connector, several different types of signals can be processed. This enables a wider range of accessories to be used with the host device while keeping the connectors small and making them more versatile. 
     Data to and from connector  100  is multiplexed by serializer/de-serializer circuitry on both the plug connector and receptacle connector sides as shown in  FIG. 4 . When connector  100  is used to support relatively simple functions, such as headphone mode or charger/sync mode, the serializer/de-serializer circuitry may not be necessary and instead appropriate pass thru circuitry can be employed as shown in  FIGS. 5 and 6 . 
     A serializer is a circuit that takes as its input n bits of parallel data changing at rate y and transforms them into a serial stream at a rate of n times y. A de-serializer is a circuit that takes as its input a serial stream at a rate of n times y and changes it into parallel data of width n changing at rate y. Using the SERDES enables transmission of data in the range of 10-15 Gbits/sec between a host device and an accessory. Thus a single port using just two pairs of contacts can be used to transmit and receive all the I/O signals between a host device and an accessory at a very high rate. 
     As illustrated in  FIG. 4 , a host device  400  is communicably coupled to an accessory  402 , e.g., using a plug connector  100  and a receptacle connector  200  described above, according to an embodiment of the present invention. As illustrated, in this embodiment, accessory  402  supports audio, HDMI, and USB signals. As is known in the art, these signals for audio, HDMI, and USB differ considerably. However, all these different types of signals are communicated between accessory  402  and host device  400  using just the four contacts on connectors  100  and  200 . 
     A serializer/de-serializer (SERDES)  404 ,  406  on the host side and the accessory side, respectively, makes the communication of these differing signals possible. In one instance, when accessory  402  wants to send HDMI and audio related signals to host  400 , SERDES  406  takes these signals and converts them into a serial stream and communicates that to host device  400 . At the other end, SERDES  404  receives this serial communication, analyzes the stream to determine the type of signals being received. Once the type of signals are known, SERDES  404  routes the signals to the appropriate circuitry within host device  400 . Thus, in our example, the HDMI signals may be routed to a display port circuitry in host device  400  for further processing and outputting on a display device and the audio signals may be routed to audio processing circuitry for output on an audio device. Thus, any number and/or type of signals can be communicated between accessory  402  and host device  400  using just two pairs of contacts. This makes the accessory very easy to manufacture with less complexity and less cost. Also having a connector with only two contacts reduces the chances of cross-talk between adjacent signals resulting in less points of possible failures. 
     However, since plug connector  100  is orientation agnostic, it may be beneficial to first determine the orientation of plug connector  100  with respect to receptacle connector  200 . Once the orientation is determined and the signals on the contacts of plug connector  100  are known, the contacts in receptacle connector  200  can be configured accordingly. For instance, continuing our above example, it would be beneficial for the host device to know (a) which signals can be sent by the accessory on each of the four contacts of the plug connector and (b) which contact of the plug connector is coupled to which contact of the receptacle connector of the host device. Once this information is known, the host device can couple the contacts in the receptacle connector with the appropriate circuitry within the host device. 
     For example, consider that contact  104   a  of plug connector  100  carries an audio signal, contact  104   b  of plug connector  100  carries a power (voltage signal), and contact  104   c  of plug connector  100  carries the HDMI signal. Further consider that contact  104   a  is physically coupled to contact  206   (1)  of receptacle connector  200 , contact  104   b  is physically coupled to contact  206   (2) , and contact  104   c  is physically coupled to contact  206   (3) . Before communication between the accessory and the host device can occur, it may be necessary that this information be known to the host device so that the host device can properly couple the contacts in the receptacle connector to the appropriate circuitry. In other words, the host device may determine the orientation of the plug connector with respect to the receptacle connector. One technique that can be used to determine the orientation information is described below. 
       FIG. 7  is a flow diagram of a process  700  for determining orientation of the plug connector with respect to the receptacle connector according to an embodiment of the present invention. Process  700  can be performed by, e.g., host device  400  of  FIG. 4 . 
     Initially, the host device can detect whether an accessory is coupled to the host device ( 702 ). In one embodiment, the host device can detect that the retention mechanism of the host device receptacle connector has engaged with pockets  106   a  and  106   b  of a plug connector of the accessory. Thereafter, the host device can monitor two contacts (a first contact and a second contact) of the receptacle connector to determine whether there is power, e.g., 5V, on any one of those two contacts ( 704 ). For example, the host device may monitor receptacle contacts corresponding to contacts  104   a  and  104   d  of the plug connector to determine whether there is power on any of those contacts. If yes, process  700  proceeds as illustrated in  FIG. 7C . 
     As shown in  FIG. 7C , if power is detected on either of the two contacts, the host device may determine whether there is power on the first contact ( 724 ). If it is determined that there is power on the first contact, the host device can determine that the plug connector is connected in a first orientation with respect to the receptacle connector ( 726 ). If power is not found on the first contact then the second contact has the power and the host device may determine that the plug connector is connected in a second orientation with respect to the receptacle connector ( 728 ). Once the orientation is determined, the host device can check whether the contact that does not have the power is in a logic “high” state ( 730 ). If the contact that does not have the power is in a logic “high” state, the host device can conclude that the accessory associated with the plug connector is a USB cable ( 732 ). If the contact that does not have the power is in a logic “low” state, the host device can conclude that the accessory associated with the plug connector is a powered accessory ( 734 ). 
     Returning back to  FIG. 7A , if at block  704  it is determined that none of the first contact or the second contact has power on them, the host device can check to see if a Mickey bus (e.g., audio signal) signal is present on any of the two contacts ( 706 ). If a Mickey bus signal is detected on any one of the two contacts, the host device can determine the orientation of the plug connector based on predefined signal locations for a Mickey bus accessory ( 708 ). If the host device does not detect a Mickey bus signal on either of the two contacts, the host device may provide power (e.g., 5V) on the first contact and monitor the second contact ( 710 ). If a valid ID signal is detected on the second contact in response to providing power on the first contact ( 712 ), the host device can determine the orientation of the plug connector since now it knows the location of contact that carries the ID signal ( 714 ). 
     If no ID signal is detected on the second contact, process  700  continues as illustrated in  FIG. 7B . The host device then provides power on the second contact and monitors the first contact ( 716 ). If a valid ID signal is detected on the first contact ( 718 ), the host device can determine orientation of the plug connector as described above ( 720 ). However, if no ID signal is detected on the first contact, the host device can conclude that the plug connector is associated with a USB cable and may wait for power to be supplied over one of the contacts of the plug connector ( 722 ). 
     It should be appreciated that the specific steps illustrated in  FIGS. 7A-C  provide a particular method of determining orientation according to an embodiment of the present invention. Other sequences of steps may also be performed according to alternative embodiments. For example, alternative embodiments of the present invention may perform the steps outlined above in a different order. Moreover, the individual steps illustrated in  FIGS. 7A-C  may include multiple sub-steps that may be performed in various sequences as appropriate to the individual step. Furthermore, additional steps may be added or removed depending on the particular applications. One of ordinary skill in the art would recognize many variations, modifications, and alternatives. 
     As will be understood by those skilled in the art, the present invention may be embodied in other specific forms without departing from the essential characteristics thereof. For example, while embodiments of the invention discussed above with respect to data plugs having twelve contacts, the invention is not limited to any particular number of contacts or any particular type of connector. As another example, while many of the plug connectors discussed above included ground rings that completely surrounded (in the horizontal plane) the contacts formed on the upper and lower surfaces of the connectors, in other embodiments ground structures can be employed that only partially surround the contacts. 
     Additionally, some embodiments of the invention may have as few as two contacts while other embodiments can have thirty or even more contacts. Similarly, embodiments of the invention are not limited to data connectors. Also, any of the connectors discussed herein can be modified to include one or more fiber optic cables that extend through the connector and can be operatively coupled to receive or transmit optical data signals between a mating connector jack. Those skilled in the art will recognize, or be able to ascertain using no more than routine experimentation, many equivalents to the specific embodiments of the inventions described herein. Such equivalents are intended to be encompassed by the following claims.