1. Field of the Invention
The present invention relates to the field of connectors, more specifically to the field of high-speed connectors suitable for use in data transmission.
2. Description of Related Art
Connectors are commonly used to couple a communication circuit on a first circuit board to a communication circuit on a second circuit board. For example, a connectors system can include a plug and a receptacle, with the receptacle mounted to a circuit board and a plug mounted on an end of a cable.
As is known, increasing the distance that the signal needs to travel (e.g., using a longer cable) increases the difficulty of transmitting a signal. Signals become more attenuated as the cable lengths increase. In addition, higher frequencies tend to be attenuated more quickly in cables. Compounding this issue is the fact that greater lengths of cable tends to pick up more noise. As can be appreciated, therefore, decreasing the signal strength while increasing the signal noise will eventually make it so that the signal cannot be discerned over the signal noise. This natural occurrence acts to limit the length of cable that can be used.
To address the above issues, different communication protocols use different techniques to address the issue. Gigabit Ethernet, for example, which is intended to be run over twisted-pair, such as Category 5e or Category 6 cable, limits segment lengths to 100 meters and uses 5 level pulse amplitude modulation (PAM-5) to limit the need for high frequencies. 10GBASE-T (also referred to as IEEE 802.3an) also works over twisted pair but uses 16 level pulse amplitude modification (PAM-16) to achieve the higher data rates. Current connector designs appear to provide 55 meters with Category 6 cables and new cable (Category 6a) is being planned to allow the desired 100 meter segment lengths. The need to upgrade cable in order to provide 10GBASE-T, however, makes the upgrade path less desirable and therefore certain people would appreciate a design that could help enable 100 meter segments of 10GBASE-T over category 6 or even 5e cable. Further improvements would also benefit the system, potentially reducing the cost of transceiver circuitry.
A connector is disclosed that is suitable for use with cables that include twisted pair wires. The connector includes a cage mounted at least partially around a housing. In an embodiment, a wire module is positioned in the housing and is configured to receive wires from the twisted pair cable. A leadframe that supports terminals is also positioned in the housing and the leadframe includes an insulation displacement feature. The cable module and leadframe are configured to be pressed together so that insulated conductive members from the twisted pair cable are mounted to the insulation displacement feature. The housing can be configured so that the connector is compatible with the receptacle designed for the commonly used IEC 60603-7 8P8C connector (commonly referred to as a RJ-45 connector). In an embodiment, magnetics can be positioned in the connector in an electrical path between the insulation displacement feature and the contact so as to provide improved signal to noise ratios.
The present invention is illustrated by way of example and not limited in the accompanying figures in which like reference numerals indicate similar elements and in which:
a illustrates a schematic view of another embodiment of a cable assembly.
The detailed description that follows describes exemplary embodiments and is not intended to be limited to the expressly disclosed combination(s). Therefore, unless otherwise noted, features disclosed herein may be combined together to form additional combinations that were not otherwise shown for purposes of brevity.
When upgrading a local area network, one common desire is to be able to change the devices on the end and continue to use the existing cables. Fiber optic cables tend to be well suited for this as it is often possible to send additional wavelengths of light over the same optical cable if there is a desire to increase the data rate. Many networks, however, are copper wires, typically in a twisted pair configuration. Twisted-pair cables are relatively simple to route, are resistant to damage during installation and have provided acceptable data rates.
The continued information explosion, along with the recent determination that it would be beneficial to be able to stream much higher bandwidth than is currently possible over most home networks makes existing networks somewhat constraining. For example, a 100 mbps Ethernet connection is unlikely to be sufficient to allow for multiple high definition streams, particularly if lossless audio is included. Furthermore, uncompressed high definition streams (which require less computation power to process as there is no need to compress and uncompress the stream) are expected to require 3 Gbps or more. Therefore, it has been determined that a system that could allow for increased data rates over existing twisted pair cable would be desirable.
Before turning to the figures, however, it should be noted that a transmission system is a sum of it parts. In other words, a signal transmitted from a first circuit board to a second circuit board must travel the path between the two circuit boards. Therefore, the depicted connector systems can be used in Gigabit Ethernet and 10GBASE-T Ethernet systems but the performance of the transmission system will vary based on a number of things such as the performance of the cable (whether it is Cat 5, Cat 5e or Cat 6 cable, for example) and the level of the signal and the noise of the environment. For shorter segments, which tend to experience less noise due to external signals, it is expected that the need for magnetic filtering can sometimes be avoided. For longer segments or for applications where improvements to the signal to noise ratio would be a benefit, however, the use of magnetic filtering as disclosed may prove to be particularly beneficial.
Turning to
On a first side 10a of the connector (which also includes sides 10b, 10c, 10d, 10e and 10f), a crimp tab 26 is provided in the cage 20 (as depicted, two crimp tabs 26 are disclosed but a single crimp tab can be used if desired). The crimp tab 26, which is shown in a first position, is configured to be pressed into aperture 61 so that it engages first surface 86 of cable module 60 and in operation presses the cable module 60 toward a leadframe 100.
A relief brace 40 is mounted on legs 22 of the cage 20 and the legs 22 include projections 23. The relief brace 40 includes slots that are configured to allow the relief brace 40 to be mounted to the legs. When crimped, the projections 23 are bent over a retaining ledge 42a so that the projections 23 extend into a retaining groove 42b. A bottom surface 39, which may include retaining ribs 39a, acts to press against a coupled cable once the relief brace is crimped in place and helps provide strain relief for the cable.
As can be appreciated from
As depicted, and to help hold the connector 10 together, the cage 20 wraps around four sides of the connector and fingers 28, 29 engage locking slots 104, 106 to help ensure the connector is securely held together.
The plug 10 includes a plurality of terminals (typically 8 for a connector configured for 4 twisted-pair cable) positioned in terminal slots 54. To electrically couple the terminals to the wires in the attached cable, an outer layer of the cable is removed and the wires that make up the twisted pairs are inserted into wire channels 84 in a face 83 of wire module 80. As depicted, the wire channels 84 and the wire channels include ends 81 that are open on one side. As depicted, the ends 81 are alternatively short and long and include side groove 81, 81b that are configured to receive insulation displacement member 120. The wire module 80 includes a ledge 82 that in operation squeezes the cable between the ledge 82 and the bottom surface 39 when the crimp tab 26 presses against surface 86 (which may include ribs 86a that can be position between tabs 427 of crimp tab 426—see
As can be appreciated, therefore, the cage 20 can include a number of differently configured crimp tabs 26 (as well as a number of variations in the actuator 43). Furthermore, when looking at the embodiment that includes magnetic filter (
The connector 10 includes a leadframe 100, which is depicted in
As can be appreciated from
The insulation displacement portion 120 includes a base 121 with a terminal receiving slot 126 and two wire engaging flanges 122, 124. The wire engaging flanges 122, 124 are positioned and configured so that when the insulation displacement portion 120 is inserted into the end 81 of the wire channel 84, the flanges 122, 124 pierce the insulation of the wire positioned in the wire channel and provide a solid electrical connection between the wire and the terminal 70.
It should be noted that the depicted connectors are typically used with twisted-pair wires that form a differential mode (for example, 4 twisted-pair wires can be provided in a cable, each forming a differential signal channel). While not desired, in general, it is extremely difficult to avoid the generation of a common mode when using a differential signal channels over twisted pairs. Compared to conventional insulation displacement terminals used in RJ-45 connectors, however, the improved insulation displacement portions, along with disclosed terminal design, substantially reduces conversion of the common mode to differential mode.
To provide for higher performance, separation notches 112 in the leadframe 100 may be positioned between adjacent insulation displacement portions 120 in a row. The separation notches act to increase the electrical separation and thus help further reduce cross talk. If desired, further improvements to the performance of the connector would be possible if the insulation displacement portions where alternatively arranged on the top and bottom of the leadframe so as to provide greater isolation between differential pairs, thus reducing cross talk and helping to improve the signal to noise ratio.
As in the previous embodiment, the cage 420 includes fingers 428, 429 that engage locking slots in a leadframe 300. Similarly, terminals 270 are positioned in terminal slots 254.
One difference between the previous embodiment and the embodiment depicted in
The embodiment depicted in
As depicted, the leadframe 300 includes magnetics 301 (which as depicted consist of a plurality of chokes 305 that include apertures 306) positioned between insulation displacement portions 120 and contacts 272. It should be noted that the magnetics are not required to be so positioned but such placement helps reduce the overall size of the connector, which is generally desirable. More generally, however, it is sufficient to position the magnetics so as to integrate it into the connector so that the magnetics are in the electrical path between the contacts and the insulation displacement.
To place the magnetics 301 in the electric path between the insulation displacement portions 120 and the contacts 272, the terminal can be split into a first terminal portion 270a and a second terminal portion 270b. The first terminal portion 270a includes a first coupling portion 276 and a wire tab 273 and a body portion 275a extending therebetween. The second terminal portion 270b includes an end 274 and the contact 272 and a wire tab 271 with a body portion extending between the contact 272 and the wire tab 271.
As can be appreciated from
As can be appreciated from
One issue with the legacy split pair design is that once the different signal pair becomes split, the different coupling is diminished and the split-pair because much more susceptible to noise. The embodiment provided in
As depicted, the chokes 305 are not shown with anything holding them in position. In an embodiment, a foam (such as a silicone-based foam) can be used to hold the chokes in position. In another embodiment, the chokes can be potted into position. In another embodiment, ribs such as ribs 330 can be used to hold the chokes in position. Thus, unless otherwise noted, the method of securing the chokes into position is not intended to be limiting.
It should be noted that while a plurality of chokes 305 with a single opening 306 can be used, a dual choke 325 with openings 327 and 328 that extend between face 326a and face 326b can also be used. The wires 310, 312 aligned with a first pair of terminals wrap around opening 327 and wires aligned with a second pair of terminals wrap around opening 328.
Regardless of the configuration of the latch, the leadframe 300 or the leadframe 100 can be used. Thus, a connector compatible with the RJ-45 receptacle could include magnetics or omit the magnetics, depending on whether the application would benefit from the filtering. Similarly, a connector with the latch side latch release configuration as illustrated in
Therefore, as depicted in
As can be appreciated from
The depicted embodiments have been described in terms of preferred and exemplary embodiments thereof. Numerous other embodiments, modifications and variations within the scope and spirit of the appended claims will occur to persons of ordinary skill in the art from a review of this disclosure.
This application is a national phase of PCT Application No. PCT/US2010/034855, filed May 14, 2010, which in turn claims priority to U.S. Provisional Application No. 61/178,925, filed May 15, 2010, which is incorporated herein by reference in its entirety.
Filing Document | Filing Date | Country | Kind | 371c Date |
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PCT/US2010/034855 | 5/14/2010 | WO | 00 | 1/25/2012 |
Publishing Document | Publishing Date | Country | Kind |
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WO2010/132739 | 11/18/2010 | WO | A |
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61178925 | May 2010 | US |