Abstract:
The present disclosure relates generally to connectors such as audio and data connectors and in particular to low profile audio connectors that can be used in place of standard audio and data connectors currently used. The plug connector has a reduced plug length and thickness, an intuitive insertion orientation and a smooth, consistent feel when inserted and extracted from its corresponding receptacle connector. The plug connector may be characterized by a flat tip portion at its distal end, a base portion near its proximal end, a shell coupled at the base portion and a plurality of external contacts.

Description:
CROSS-REFERENCES TO RELATED APPLICATIONS 
       [0001]    This application claims the benefit of U.S. Prov. Pat. App. No. 61/357,023, filed Jun. 21, 2010, and titled “EXTERNAL CONTACT AUDIO CONNECTOR,” which is incorporated herein by reference for all purposes. 
     
    
     FIELD OF INVENTION 
       [0002]    The present invention relates generally to connectors such as audio connectors and data connectors and in particular to low profile audio connectors and data connectors that can be used in place of standard audio connectors currently used. 
       BACKGROUND OF THE INVENTION 
       [0003]    The present invention relates generally to input/output electrical connectors such as audio connectors and data connectors. 
         [0004]    Standard audio connectors or plugs are available in three sizes according to the outside diameter of the plug: a 6.35 mm (¼″) plug, a 3.5 mm (⅛″) miniature plug and a 2.5 mm ( 3/32″) subminiature plug. The plugs include multiple conductive regions that extend along the length of the connectors in distinct portions of the plug such as the tip, sleeve and one or more middle portions between the tip and sleeve resulting in the connectors often being referred to as TRS (tip, ring and sleeve) connectors. 
         [0005]      FIGS. 1A and 1B  illustrate examples of audio plugs  10  and  20  having three and four conductive portions, respectfully. As shown in  FIG. 1A , plug  10  includes a conductive tip  12 , a conductive sleeve  16  and a conductive ring  14  electrically isolated from the tip  12  and the sleeve  16  by insulating rings  17  and  18 . The three conductive portions  12 ,  14 ,  16  are for left and right audio channels and a ground connection. Plug  20 , shown in  FIG. 1B , includes four conductive portions: a conductive tip  22 , a conductive sleeve  26  and two conductive rings  24 ,  25  and is thus sometimes referred to as a TRRS (tip, ring, ring, sleeve) connector. The four conductive portions are electrically isolated by insulating rings  27 ,  28  and  29  and are typically used for left and right audio, microphone and ground signals. As evident from  FIGS. 1A and 1B , each of audio plugs  10  and  20  are orientation agnostic. That is, the conductive portions completely encircle the connector forming 360 degree contacts such that there is no distinct top, bottom or side to the plug portion of the connectors. 
         [0006]    When plugs  10  and  20  are 3.5 mm miniature connectors, the outer diameter of conductive sleeve  16 ,  26  and conductive rings  14 ,  24 ,  25  is 3.5 mm and the insertion length of the connector is 14 mm. For 2.5 mm subminiature connectors, the outer diameter of the conductive sleeve is 2.5 mm and the insertion length of the connector is 11 mm long. Such TRS and TRRS connectors are used in many commercially available MP3 players and smart phones as well as other electronic devices. Electronic devices such as MP3 players and smart phones are continuously being designed to be thinner and smaller and/or to include video displays with screens that are pushed out as close to the outer edge of the devices as possible. The diameter and length of current 3.5 mm and even 2.5 mm audio connectors are limiting factors in making such devices smaller and thinner and in allowing the displays to be larger for a given form factor. 
         [0007]    Many standard data connectors are also only available in sizes that are limiting factors in making portable electronic devices smaller. Additionally, and in contrast to the TRS connectors discussed above, many standard data connectors require that they be mated with a corresponding connector in a single, specific orientation. Such connectors can be referred to as polarized connectors. As an example of a polarized connector,  FIGS. 2A and 2B  depict a micro-USB connector  30 , the smallest of the currently available USB connectors. Connector  30  includes a body  32  and a metallic shell  34  that extends from body  32  and can be inserted into a corresponding receptacle connector. As shown in  FIGS. 2A ,  2 B, shell  34  has angled corners  35  formed at one of its bottom plates. Similarly, the receptacle connector (not shown) with which connector  30  mates has an insertion opening with matching angled features that prevents shell  34  from being inserted into the receptacle connector the wrong way. That is, it can only be inserted one way—in an orientation where the angled portions of shell  34  align with the matching angled portions in the receptacle connector. It is sometimes difficult for the user to determine when a polarized connector, such as connector  30  is oriented in the correct insertion position. 
         [0008]    Connector  30  also includes an interior cavity  38  within shell  34  along with contacts  36  formed within the cavity. Cavity  38  is prone to collecting and trapping debris within the cavity which may sometimes interfere with the signal connections to contacts  36 . Also, and in addition to the orientation issue, even when connector  30  is properly aligned, the insertion and extraction of the connector is not precise, and may have an inconsistent feel. Further, even when the connector is fully inserted, it may have an undesirable degree of wobble that may result in either a faulty connection or breakage. 
         [0009]    Many other commonly used data connectors, including standard USB connectors, mini USB connectors, FireWire connectors, as well as many of the proprietary connectors used with common portable media electronics, suffer from some or all of these deficiencies or from similar deficiencies. 
       BRIEF SUMMARY OF THE INVENTION 
       [0010]    Various embodiments of the invention pertain to plug connectors and receptacle connectors that improve upon some or all of the above described deficiencies. Other embodiments of the invention pertain to methods of manufacturing such plug and/or receptacle connectors as well as electronic devices that include such connectors. Embodiments of the invention are not limited to any particular type of connector and may be used for numerous applications. Some embodiments, however, are particularly well suited for use as audio connectors and some embodiments are particularly well suited for data connectors. 
         [0011]    In view of the shortcomings in currently available audio and data connectors as described above, some embodiments of the present invention relate to improved audio and/or data plug connectors that have a reduced plug length and thickness, an intuitive insertion orientation and a smooth, consistent feel when inserted and extracted from its corresponding receptacle connector. Additionally, some embodiments of plug connectors according to the present invention have external contacts instead of internal contacts and do not include a cavity that is prone to collecting and trapping debris. The contacts can be symmetrically spaced on one or both of the first and second major opposing sides. The plug connector can have a 180 degree symmetrical shape so that it can be inserted and operatively coupled to a corresponding receptacle connector in either of two insertion orientations. In some embodiments, the connector tab includes at least one retention feature, e.g., notches, adapted to engage with a retention feature, e.g., protrusions, on a corresponding receptacle connector. In some further embodiments the plug connector includes one or more ground contacts formed on the side surfaces or the retention features of the plug connector. 
         [0012]    In one embodiment, a plug connector according to the present invention includes a metal plate and a dielectric spacer. The metal plate has a substantially flat tip portion at its distal end with first and second opposing major sides and a central opening formed through the metal plate. The dielectric spacer has a substantially flat tip portion formed within the opening in the metal plate and a base portion that is thicker than the tip portion formed at a proximal end of the metal plate. The spacer further includes a first and second opposing outer surfaces that extend from the tip portion to the base portion and a plurality of slots formed at each of the first and second outer surfaces. A plurality of external contacts positioned within the plurality of slots in the dielectric spacer. 
         [0013]    A plug connector according to another embodiment of the invention comprises a dielectric core and a plurality of external contacts. The dielectric core has first and second opposing major surfaces and a plurality of grooves formed within each of the first and second major surfaces where the grooves are symmetrically formed on left and right halves of the dielectric core. The plurality of contacts includes a set of contacts positioned within the plurality of grooves in the dielectric core. The plug connector has a substantially flat tab portion at its distal end on which at least a portion of the plurality of external contacts are carried. 
         [0014]    A plug connector according to yet another embodiment of the invention comprises a plug body having a substantially flat tab portion and first and second opposing major surfaces and a plurality of contacts positioned on the first and second opposing surfaces in a 180 degree symmetric relationship so the plug connector can be inserted into a corresponding receptacle connector in either of two positions. In some embodiments, the plug body comprises a ceramic core and includes a plurality of grooves formed on the first and second opposing surfaces in corresponding to the plurality of contacts. In other embodiments, the plug body comprises a metal core and a recessed area formed the first and second opposing surfaces, and the plurality of external contacts are formed on a flex circuit that is adhered to the metal core in the recessed area. 
         [0015]    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 
         [0016]      FIGS. 1A and 1B  show perspective views of previously known TRS audio plug connectors; 
           [0017]      FIG. 2A  shows a perspective view of a previously known micro-USB plug connector while  FIG. 2B  shows a front plan view of the micro-USB connector shown in  FIG. 2A ; 
           [0018]      FIG. 3  is a simplified perspective view of an plug connector according to one embodiment of the present invention; 
           [0019]      FIG. 4A  is a simplified exploded perspective view of the connector  40  shown in  FIG. 3 ; 
           [0020]      FIG. 4B  is a simplified cross-sectional view of connector  40  shown in  FIG. 3  taken across lines A-A′ shown in  FIG. 3 ; 
           [0021]      FIG. 5A  is a simplified exploded perspective view of a plug connector  60  according to another embodiment of the present invention; 
           [0022]      FIG. 5B  is a simplified cross-sectional view of plug connector  60  shown in  FIG. 5A  taken along the same A-A′ lines as the cross-section in  FIG. 4B ; 
           [0023]      FIG. 6A  is a simplified exploded perspective view of a plug connector  80  according to another embodiment of the present invention; 
           [0024]      FIG. 6B  is a simplified cross-sectional view of plug connector  80  shown in  FIG. 6A  taken along the same A-A′ lines as the cross-section in  FIG. 4B ; 
           [0025]      FIG. 7A  is a simplified exploded perspective view of a plug connector  100  according to another embodiment of the present invention; 
           [0026]      FIG. 7B  is a simplified cross-sectional view of plug connector  100  shown in  FIG. 7A  taken along the same A-A′ lines as the cross-section in  FIG. 4B ; 
           [0027]      FIG. 8A  is a simplified exploded perspective views of a plug connector  120  according to another embodiment of the present invention; and 
           [0028]      FIG. 8B  is a simplified cross-sectional view of plug connector  120  shown in  FIG. 8A  taken along the same A-A′ lines as the cross-section in  FIG. 4B . 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       [0029]    Embodiments of the present invention are suitable for a multiplicity of electronic devices, including any device that receives or transmits audio, video or data signals among others. In some instances, embodiments of the invention are particularly well suited for portable electronic media devices because of their potentially small form factor. As used herein, an electronic media device includes any device with at least one electronic component that may be used to present human-perceivable media. Such devices may include, for example, portable music players (e.g., MP3 devices and Apple&#39;s iPod devices), portable video players (e.g., portable DVD players), cellular telephones (e.g., smart telephones such as Apple&#39;s iPhone devices), video cameras, digital still cameras, projection systems (e.g., holographic projection systems), gaming systems, PDAs, desktop computers, as well as tablet (e.g., Apple&#39;s iPad devices), laptop or other mobile computers. Some of these devices may be configured to provide audio, video or other data or sensory output. 
         [0030]    In order to better appreciate and understand the present invention, reference is first made to  FIG. 3  which is a simplified perspective view of a first embodiment of an audio or data plug connector  40  according to the present invention. As shown in  FIG. 3 , connector  40  includes a substantially flat tab  41  that extends from a shell  50 . Tab  41  includes a front major surface  43   a  upon which two contacts  44   a  and  44   b  are positioned and a back major surface  43   b  upon which two contacts  44   c  and  44   d  are located ( 43   b ,  44   c , and  44   d  are not visible in  FIG. 3 ). Two substantially thinner sides  43   c  and  43   d  (shown in  FIG. 4B ) extend between the front and back major surfaces. 
         [0031]    In one particular embodiment, connector  40  is an audio plug connector and contact  44   a  is a left audio contact, contact  44   b  is a microphone contact, contact  44   c  (not visible in  FIG. 3 ) is a right audio contact, and contact  44   d  (not visible in  FIG. 3 ) is a second microphone contact. The contacts can be made from a copper, nickel, brass, a metal alloy or any other appropriate conductive material. Spacing is consistent between each pair of contacts  44   a ,  44   b  and  44   c ,  44   d  providing 180 degree symmetry so that plug connector  40  can be inserted into a corresponding receptacle connector in either of two orientations. For example, when connector  40  is mated with a corresponding receptacle jack, each of contacts  44   a - 44   d  is in electrical contact with a corresponding contact in the receptacle jack. Additionally, the two audio contacts  44   a  and  44   c  are located on opposite sides of the connector in a cater cornered arrangement (see  FIG. 4B ). Thus, microphone contact  44   d  is located directly opposite audio contact  44   a  and microphone contact  44   b  is located directly opposite audio contact  44   c . In this manner, an audio contact is always on the right side of the connector and a microphone contact is always on the left side of the connector (as oriented from the connecter base to its distal end). A sensing circuit in the receptacle jack or the electronic device in which the receptacle jack is housed can detect the direction that the contacts  44   a - 44   d  are set and switch internal connections to the contacts in the connector jack as appropriate. For example, a software switch can be used to switch the receptacle jack&#39;s contacts for left and right audio depending on the insertion orientation while a hardware switch can be used to switch the connector jacks microphone and ground contacts to match the contacts of connector  40 . In other embodiments, both switches can be implemented in software or both switches can be implemented in hardware. In another example, the orientation of the connector can instead be detected by circuitry associated with the corresponding receptacle connector based on signals received over the contacts. As one example, upon inserting a connector within a receptacle connector of a host device, the host device may send an Acknowledgment signal to the serial control chip over the contact in the receptacle connector designated for the specific contact and waits for a Response signal. If a Response signal is received, the contacts are aligned properly and audio and other signals can be transferred between the connectors. If no response is received, the host device flips the signals to correspond to the second possible orientation (i.e., flips the signals 180 degrees) and repeats the Acknowledgement/Response signal routine. In another embodiment, a physical orientation key (e.g., a unique notch or other physical features) formed on the plug connector, can be detected by an orientation contact or other appropriate mechanism in the receptacle connector to determine the orientation of the plug, and a hardware or software switch can set the receptacle connector contacts as appropriate for left and right audio or other data contacts to correspond to the plug connector contacts. 
         [0032]    Two retention features, shown as V-shaped notches  45   a  and  45   b  in  FIG. 3 , are formed on opposing sides of tab  41  near its distal end. When tab  41  is inserted into a receptacle connector, notches  45   a  and  45   b  operatively engage with a retention mechanism, such as a cantilevered spring or detent, within the receptacle connector. In other embodiments, other retention mechanisms can be used such as mechanical or magnetic latches or orthogonal insertion mechanisms. Although retention features  45   a  and  45   b  shown in  FIG. 3  are V-shaped notches, they may also be round notches (e.g., c-shaped or semi-circular notches), pockets, indentations, or similar recessed regions formed on each of the side surfaces  43   c ,  43   d  ( 43   d  is not visible in  FIG. 3 ) that can operatively engage with a retention feature or mechanism in a corresponding receptacle connector. Connector  40  also includes a chamfered edge  43   e  surrounding tab  41  and extending from the upper and lower major surfaces  43   a ,  43   b  and thinner side surfaces  43   c ,  43   d  (not visible in  FIG. 3 ) of the tab to base portion  42  (shown in  FIG. 4A ) of the connector that can be inserted within shell  50  (shown in  FIG. 4A ). Chamfered edge  43   e  stiffens and reinforces the connector near its base thus increasing its strength in a side-load condition. 
         [0033]    As shown in  FIG. 3 , contacts  44   a - 44   d  are external contacts and connector  40  does not include an exposed cavity in which particles and debris may collect. To improve robustness and reliability, connector  40  is fully sealed and includes no moving parts. Furthermore, connector  40  has a considerably reduced insertion depth and insertion width as compared to commonly available TRS and TRRS connectors described above. In one particular embodiment, tab  41  of connector  40  has a width, X (shown in  FIG. 4B ), of 2 mm; a thickness, Y (shown in  FIG. 4B ), of 1 mm; and an insertion depth, Z, of 4 mm. In another embodiment, tab  41  of connector  40  has a width, X, of 4.1 mm; a thickness, Y, of 1.5 mm; and an insertion depth, Z, of 5.75 mm. 
         [0034]    In other embodiments, connector  40  may include more than four contacts (with corresponding slots) total or more than four contacts (with corresponding slots) on each of surfaces  43   a  and  43   b , e.g., 6, 8, 10, or more contacts and there may also be ground contacts at the distal tip of connector  40  or on side surfaces  43   c  and  43   d . Where connector  40  is a data plug connector, many different types of digital signals can be carried by four or more contacts including data signals such as, USB signals (including USB 1.0, 2.0 and/or 3.0), FireWire (also referred to as IEEE 1394) signals, SATA signals and/or any other type of data signal. Other digital signals that may be carried by the contacts of connector  40  include signals for digital video such as DVI signals, HDMI signals and Display Port signals, as well as other digital signals that perform functions that enable the detection and identification of devices, electronic media devices or accessories to connector  40 . 
         [0035]      FIG. 4A  is a simplified exploded perspective view of connector  40  that better depicts how the various components of the connector are fabricated and joined together according to one particular embodiment of the invention. Connector  40  is formed around a metal plate  46  that can be stamped from high strength steel or formed in any other appropriate way. An insulation spacer  48  is molded around the metal plate  46  so that the combination of plate  46  and insulation spacer  48  define the basic shape of tab  41 , base portion  42  and the chamfered edge  43   e  that extends between tab  41  and base portion  42 . Two slots  47   a ,  47   b  are formed in an upper surface of insulation spacer  48  and two slots  47   c ,  47   d  (not visible in  FIG. 4A ) are formed in a lower surface of the spacer. 
         [0036]    Contacts  44   a - 44   d  can be stamped from sheet metal formed in a sintering process from a metal powder or made according to other known techniques and inserted their respective slots,  47   a - 47   d . Signal wires (not shown) are soldered to each of the contacts in an area within base  42  of the connector and a ground wire is soldered to metal plate  46  to provide a ground contact for connector  40 . The wires extend through the connector to cord  52  that is coupled at its other end to an electronic device, such as a stereo headset. An ABS or similar shell  50  is positioned over and then fastened to base  42  of the connector to complete its formation. 
         [0037]    Reference is now made to  FIGS. 5A and 5B  in which  FIG. 5A  is a simplified exploded perspective view of a plug connector  60  according to another embodiment of the present invention and  FIG. 5B  is a simplified cross-sectional view of plug connector  60  shown in  FIG. 5A  taken along the same cross-section of the connector in  FIG. 4B . Connector  60  includes four signal contacts  64   a - 64   d  farmed around a dielectric plate  66  and a ground contact  64   e  that runs through the center of the connector. In one embodiment, contact  64   a  is a left audio contact, contact  64   b  is a microphone contact, contact  64   c  is a right audio contact and contact  64   d  is a second microphone contact. As shown in  FIG. 5B , the contacts are arranged on a substantially flat tab portion of connector  60  to have a 180 degree symmetrical design similar to that of connector  40 . A sensing circuit in the receptacle jack or the electronic device in which the receptacle jack is housed can detect the direction that contacts  64   a - 64   d  are set and switch internal connections to the contacts in the connector jack as appropriate. 
         [0038]    Dielectric core  66  can be molded from a thermoplastic polymer or similar material around ground contact  64   e . Slots  67   a - 67   d  ( 67   c  and  67   c  are not visible in  FIG. 5A ) are formed in core  66  for contacts  64   a - 64   d  which can be wire formed or stamped from sheet metal and bent. Slots  67   a - 67   d  include ribs  68   a ,  68   b  that align with grooves  69   a ,  69   b  formed in the corresponding contacts. Grooves  69   a ,  69   b  provide shear strength in bending for the contacts. Connector  60  is designed so that contacts  64   a - 64   d  provide much of the strength of the plug. Similar to connector  40 , connector  60  also has a chamfered edge between its tab and base portions that may reinforce the connector near its base thus increasing its strength in a side-load condition. Additionally, retention features, shown as small V-shaped notches  71  in  FIG. 5A , is formed in each of contacts  64   a - 64   d  that aligns with retention features, shown as V-shaped notches  65   a ,  65   b  in  FIG. 5A , formed in dielectric core  66 . In some embodiments, the shape of the retention features of connector  60  may be varied as discussed with reference to the retention features of connector  40 . Once the contacts are adhered within their respective slots, core  66  can be slid within and bonded to an ABS or similar shell  70 . 
         [0039]    As with connector  40 , contacts  64   a - 64   d  are external contacts and connector  60  does not include an exposed cavity in which particles and debris may collect. To improve robustness and reliability, connector  60  is also fully sealed and includes no moving parts. Furthermore, connector  60  has a considerably reduced insertion depth and insertion width as compared to commonly available TRS and TRRS connectors described above. In one particular embodiment, the insertion portion of connector  60  has a width, X, of 2 mm; a thickness, Y, of 1 mm; and an insertion depth, Z (as measured in  FIG. 3 ), of 4 mm. In another embodiment, the insertion portion of connector  60  has a width, X, of 4.1 mm; a thickness, Y, of 1.5 mm; and an insertion depth, Z (as measured in  FIG. 3 ), of 5.75 mm. 
         [0040]    In some embodiments, as with connector  40 , connector  60  may include more than four contacts (with corresponding slots) total or more than four contacts (with corresponding slots) on each of major surfaces  63   a  and  63   b  (shown if  FIG. 5B ), e.g., 6, 8, 10, or more contacts and there may also be ground contacts formed on side surfaces  63   c  and  63   d . Where connector  60  is a data plug connector, many different types of digital signals can be carried by four or more contacts including data signals such as, USB signals (including USB 1.0, 2.0 and/or 3.0), FireWire (also referred to as IEEE 1394) signals, SATA signals and/or any other type of data signal. Other digital signals that may be carried by the contacts of connector  40  include signals for digital video such as DVI signals, HDMI signals and Display Port signals, as well as other digital signals that perform functions that enable the detection and identification of devices, electronic media devices or accessories to connector  40 . 
         [0041]    A connector  80  according to another embodiment of the present invention is shown in  FIGS. 6A and 6B  in which  FIG. 6A  is a simplified exploded perspective view of the plug connector  80  and  FIG. 6B  is a simplified cross-sectional view of connector  80  taken along the same cross-section of the connector as in  FIGS. 4B and 5B . Connector  80  includes a substantially flat tab  81  that extends from a shell  90 . Tab  81  includes a front major surface  83   a  upon which two contacts  84   a  and  84   b  are positioned and a back major surface  83   b  upon which two contacts  84   c  and  84   d  are located. Additionally, a fifth contact  84   e  extends through the center of connector  80  and is located at distal end  89  of the connector. 
         [0042]    In one particular embodiment, contact  84   a  is a left audio contact, contact  84   b  is a microphone contact, contact  84   c  is a right audio contact, contact  84   d  is a second microphone contact, contact  84   e  is a ground contact and the contacts are positioned on connector  80  so that it has a 180 degree symmetrical design similar to that of connectors  40  and  60  so that plug connector  80  can be inserted into a corresponding receptacle connector in either of two orientations. The contacts can be made from a copper, nickel, brass, a metal alloy or any other appropriate conductive material. A sensing circuit in the receptacle jack or the electronic device in which the receptacle jack is housed can detect the direction that the contacts  84   a - 84   d  are set and switch internal connections to the contacts in the connector jack as appropriate. 
         [0043]    Two retention features, shown as V-shaped notches  85   a  and  85   b  in  FIG. 6A , are formed on opposing sides of tab  81  near distal end  89 . When tab  81  is inserted into a receptacle connector, notches  85   a  and  85   b  operatively engage with a retention mechanism, such as a cantilevered spring or detent, within the receptacle connector. In other embodiments, other retention mechanisms can be used such as mechanical or magnetic latches or orthogonal insertion mechanisms. Connector  80  also includes a chamfered edge  83   e  surrounding tab  81  and extending from the upper and lower major surfaces  83   a ,  83   b  and the thinner side surfaces  83   c ,  83   d  of the tab to a base portion of the connector. Chamfered edge  83   e  stiffens and reinforces the connector near its base thus increasing its strength in a side-load condition. 
         [0044]    As with connectors  40  and  60 , the contacts  84   a - 84   d  of connector  80  are external contacts so the connector does not include an exposed cavity in which particles and debris may collect. Furthermore, connector  80  has a considerably reduced insertion depth and insertion width as compared to commonly available TRS and TRRS connectors described above. In one particular embodiment, tab  81  of connector  80  has a width, X, of 2 mm; a thickness, Y, of 1 mm; and an insertion depth, Z (as measured in  FIG. 3 ), of 4 mm. In another embodiment, tab  81  of connector  80  has a width, X, of 4.1 mm; a thickness, Y, of 1.5 mm; and an insertion depth, Z (as measured in  FIG. 3 ), of 5.75 mm. 
         [0045]    As shown  FIG. 6A  connector  80  is formed around a ceramic core  86  that generally defines the shape of tab  81  and base portion  82  as well as the chamfered edge  83   e  that extends between tab  81  and the base portion. Two slots  87   a ,  87   b  are formed in an upper surface of ceramic core  86 ; two slots  87   c ,  87   d  (not visible in  FIG. 6A ) are formed in a lower surface of the core; and a hole  88  traverses through the core&#39;s center. 
         [0046]    Ceramic core  86  can be formed by a ceramic injection molding (CIM) process or by a dry pressing, machining or other suitable processes. Ground contact  84   e  can be made from a metal wire or cut from sheet metal and inserted through hole  88  so that the end of the ground contact is flush with the outer edge of ceramic core  86  at distal end  89  of the connector. Contacts  84   a - 84   d  can be made from sheet metal and inserted into respective ones of slots  87   a - 87   d , and in another embodiment the contacts can be formed in a sintering process from a metal powder. 
         [0047]    In some embodiments, contacts  84   a - 84   d  can be used to carry any appropriate data signal (e.g., the data signals mentioned with reference to connector  40 ) as well as audio signals, video signals and the like. In some embodiments, there may be more than four contacts on connector  80  with corresponding slots, e.g., 6, 8, 10, or more contacts, and there may also be ground contacts in the retention features or otherwise formed on sides  83   c  and  83   d , as discussed with reference to previous embodiments. 
         [0048]    Another embodiment of the present invention is shown in  FIGS. 7A and 7B  where  FIG. 7A  is a simplified exploded perspective view of a plug connector  100  and  FIG. 7B  is a simplified cross-sectional view of connector  100  taken along the same cross-section of the connector as in  FIGS. 4B ,  5 B and  6 B. Connector  100  has six contacts  104   a - 104   f  attached to a ceramic core  106  that defines a substantially flat connector tab  101  and a base portion  102 . In one embodiment, contacts  104   a - 104   f , represent a left audio contact ( 104   a ), a ground contact ( 104   b ), a microphone contact ( 104   c ), a right audio contact ( 104   d ), a second ground contact ( 104   e ) and a second microphone contact ( 1040 . Similar to connectors  40 ,  60  and  80 , connector  100  has 180 degree symmetry (as shown in  FIG. 7B ) so that it can be inserted in a jack connector in either of two orientations. A sensing circuit in the receptacle jack or the electronic device in which the receptacle jack is housed can detect the direction that the contacts  104   a - 104   d  are set and switch internal connections to the contacts in the connector jack as appropriate. Additionally, notches  105   a ,  105   b  provide a retention feature similar to notches  45   a ,  45   b . Similar to connector  40 ,  60  and  80 , connector  100  also has a chamfered edge between tab  101  and base portion  102  that may reinforce the connector near its base thus increasing its strength in a side-load condition. 
         [0049]    Ceramic core  106  can be formed from a ceramic injection molding process among other techniques and in one particular embodiment is formed in a double shot process in which core  106  is formed in a first injection molding step that forms six slots in which contacts  104   a - 104   f  are subsequently formed with a metal injection molding process. In another embodiment contacts  104   a - 104   f  are formed using powdered metallurgy (PM) techniques. After the contacts are formed on core  106 , it is bonded within an ABS or similar shell  110  at a base portion  102  of the core. 
         [0050]    As with connectors  40 ,  60  and  80 , the contacts  104   a - 104   d  of connector  100  are external contacts so the connector does not include an exposed cavity in which particles and debris may collect. Furthermore, connector  100  has a considerably reduced insertion depth and insertion width as compared to commonly available TRS and TRRS connectors described above. In one particular embodiment, tab  101  of connector  100  has a width, X, of 2 mm; a thickness, Y, of 1 mm; and an insertion depth, Z (as measured in  FIG. 3 ), of 4 mm. In another embodiment, tab  101  of connector  100  has a width, X, of 4.1 mm; a thickness, Y, of 1.5 mm; and an insertion depth, Z (as measured in  FIG. 3 ), of 5.75 mm. 
         [0051]    In some embodiments, contacts  104   a - 104   f  can be used to carry any appropriate data signal (e.g., the data signals mentioned with reference to connector  40 ) as well as audio signals, video signals and the like. In some embodiments, there may be more than six or less than six contacts on connector  100  with corresponding slots, e.g., 4, 8, 10, or more contacts, and there may also be ground contacts in the retention features or otherwise formed on sides  103   c  and  103   d , as discussed with reference to previous embodiments. 
         [0052]      FIG. 8A  is a simplified exploded perspective views of a plug connector  120  according to yet another embodiment of the present invention and  FIG. 8B  is a simplified cross-sectional view of plug connector  120  shown in  FIG. 8A  taken along the same A-A′ lines as the cross-section in  FIG. 4B . Connector  120  includes a conductive core  126  that can be formed from a metal injection molding (MIM) process or another appropriate technique. Core  126  includes a connector tab portion  121  and a base portion  122  and acts as a carrier base for contacts  124   a - 124   d.    
         [0053]    Connector tab  121  includes upper and lower major sides  123   a  and  123   b  as well as substantially thinner sides  123   c  and  123   d  that extend between the upper and lower major sides. A chamfered edge  123   e  connects tab portion  121  to base portion  122  that stiffens and reinforces the connector near its base thus increasing its strength in a side-load condition. 
         [0054]    Retention features, shown as notches  125   a ,  125   b  in  FIG. 8A , can be formed on side surfaces  123   c ,  123   d  near a distal end of the connector and operatively engage with a retention mechanism within corresponding connector jack. Although retention features  125   a ,  125   b  in  FIG. 8A  are shown as notches, they may also be v-shaped notches, pockets, indentations, or similar recessed regions that can operatively engage with a retention feature or mechanism in a corresponding receptacle connector. On its outer surface, conductive core  126  further includes a recessed region  127  that images extends along the first major surface  123   a  at base portion  122  of core  126  down the center of the core along chamfered edge  123   e  and tab  121  and wraps around the tip  129  and, on surface  123   b  mirrors its shape on surface  123   a . A flex circuit  128  can be slipped over the end of the connector and adhered into recessed region  127 . Flex circuit may include, for example, thick copper traces that act as contacts  124   a - 124   d  coated with nickel and palladium formed on a thin polymide or PEEK (polyether ether ketone) layer. In another embodiment, the recessed region  127  does not extend around tip  129  of connector  120  and instead comprises two separate recessed regions on each of the major surfaces. In this embodiment, flex circuit  128  can be made from two separate pieces each of which is directly adhered to one of the upper and lower major sides  123   a ,  123   b  within its respective recessed region. Similar to connectors  40 ,  60 ,  80  and  100 , connector  120  has 180 degree symmetry so that it can be inserted in a jack connector in either of two orientations. A sensing circuit in the receptacle jack or the electronic device in which the receptacle jack is housed can detect the direction that the contacts  124   a - 124   d  are set and switch internal connections to the contacts in the connector jack as appropriate. Signal wires (not shown) are soldered to each of the contacts in an area within base  122  of the connector and a ground wire is soldered to conductive core  126  to provide a ground contact for connector  120 . The wires extend through the connector to cord  132  that is coupled at its other end to an electronic device, such as a stereo headset. An ABS or similar shell  130  is positioned over and then fastened to base  130  of the connector to complete its formation. 
         [0055]    As with connectors  40 ,  60 ,  80  and  100 , the contacts  124   a - 124   d  of flex circuit  128  of connector  120  are external contacts so the connector does not include an exposed cavity in which particles and debris may collect. Furthermore, connector  120  has a considerably reduced insertion depth and insertion width as compared to commonly available TRS and TRRS connectors described above. In one particular embodiment, tab  121  of connector  120  has a width, X, of 2 mm; a thickness, Y, of 1 mm; and an insertion depth, Z (as measured in  FIG. 3 ), of 4 mm. In another embodiment, tab  121  of connector  120  has a width, X, of 4.1 mm; a thickness, Y, of 1.5 mm; and an insertion depth, Z (as measured in  FIG. 3 ), of 5.75 mm. 
         [0056]    In some embodiments, contacts  124   a - 124   d  can be used to carry any appropriate data signal (e.g., the data signals mentioned with reference to connector  40 ) as well as audio signals, video signals and the like. In some embodiments, there may be more than 4 contacts on connector  100  with corresponding slots, e.g., 6, 8, 10, or more contacts, and there may also be ground contacts in the retention features or otherwise formed on sides  123   c  and  123   d , as discussed with reference to previous embodiments. 
         [0057]    When inserted into a matching connector jack, connectors according to some embodiments of the present invention are designed to break when side-loaded at a certain tension. It is preferable that the plug connector breaks as opposed to the connector jack because if the jack breaks, the electronic device in which it is housed may no longer be usable. 
         [0058]    As will be understood by those skilled in the art, the present invention may be embodied in other specific foams without departing from the essential characteristics thereof. For example, while embodiments of the invention were discussed above with respect to audio plugs having four to six contacts, the invention is not limited to any particular number of contacts. Some embodiments of the invention may have as few as two contacts while other embodiments can have thirty or even more contacts. In many of these embodiments, the contacts can be arranged to have 180 degree symmetry so that the connector can be inserted into a receptacle connector in either of two different orientations. 
         [0059]    Additionally, while the invention was described with respect to an audio connector in some cases, it is not limited to any particular type of signal and can be used to carry video and/or other signals instead of audio-related signals or in addition to audio-related signals. Also, in some embodiments, connectors according to the present invention can carry both analog and digital signals. As an example, connectors according to the present invention 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 signals between a mating connector jack. Fiber optic cables allow for high data rate transmissions and can be used for USB 4.0 compatibility (e.g., 10 GB/second data transfer). Connectors according to the present invention may include power, audio and data connections and can be used to charge a device while simultaneously providing data and audio functions. 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 invention described herein. Such equivalents are intended to be encompassed by the following claims.