High speed bypass cable for use with backplanes
A cable bypass assembly is disclosed for use in providing a high frequency transmission line that connect a chip package on a circuit board to connector spaced apart from the chip package. The bypass cable assembly has a structure that allows for low loss between the chip package and the connector. Multiple cables can be used to provide a number of differentially coupled channels.
1. A bypass cable assembly, comprising:
a chip package supported on a circuit board;
a plurality of cables including a first and second cable, each of the plurality of cables including an insulative body portion with a pair of associated signal conductors extending lengthwise through the insulative body portion, the signal conductors of each pair being spaced apart, each cable of the plurality of cables including a ground shield that extends around the insulative body portion, the ground shield and signal conductors having opposing first and second free ends, wherein the first free ends of the signal conductors are terminated to circuits on the circuit board adjacent to and in communication with the chip package; and
a connector that includes a body that supports a first pair of signal terminals and a first ground terminal in a row, the signal terminals of the first pair of signal terminals each including a contact portion and a tail portion, the tail portions of the first pair of signal terminals being connected to the signal conductors of the first cable, the first ground terminal including a contact that is positioned adjacent the contacts of the first pair of signal terminals and being connected to the ground shield of the first cable so that the connector and plurality of cables help provide a differential coupled channel between the contacts of the first pair of signal terminals and the circuit board.
2. The bypass cable assembly of claim 1 , wherein the row is a first row, the connector includes a second pair of signal terminals and a second ground terminal in a second row, the signal terminals of the second pair of signal terminals each including a contact portion and a tail portion, the tail portions of the second pair of signal terminals being connected to the signal conductors of the second cable, the second ground terminal including a contact that is positioned adjacent the contacts of the second pair of signal terminals and being connected to the ground shield of the second cable.
3. The bypass cable assembly of claim 2 , wherein the bypass cable assembly is configured to support 15 GHz signaling.
4. The bypass cable assembly of claim 2 , wherein the two rows of terminals are each supported by a separate frame that is positioned in the body.
5. The bypass cable assembly of claim 1 , wherein the first pair of signal terminals is arranged so that the pair of signal contacts have ground contacts on both sides of the pair of signal contacts and the ground shield is electrically connected to the ground contacts on both sides of the pair of signal contacts.
6. The bypass cable assembly of claim 5 , wherein a second connector connects the first free end to the circuit board adjacent the chip package so as to provide the termination.
7. The bypass cable assembly of claim 1 , wherein a second connector connects the first free end to the circuit board adjacent the chip package so as to provide the termination.
8. The bypass cable assembly of claim 1 , wherein the first cable includes a drain wire.
9. The bypass cable assembly of claim 1 , wherein the row includes a second pair of signal terminals, the first and second pair of signal terminals separated from each other by at least one terminal, wherein each terminal in the second pair of signal terminals includes a contact portion and a tail portion, the tail portions of the second pair of signal terminals connected to the pair of conductors in the second cable, wherein a second ground terminal is positioned adjacent the second pair of signal terminals and the ground shield of the second cable is connected to the second ground terminal.
10. A bypass cable assembly, comprising:
a chip package supported on a circuit board;
a plurality of cables including a first cable and a second cable, each cable of the plurality of cables including an insulative body portion with a pair of associated signal conductors extending lengthwise through the insulative body portion, the signal conductors of each pair being separated by a first spacing and further including a ground shield extending around the insulative body portion, the ground shield and signal conductors having opposing first and second free ends, wherein the first free ends of the signal conductors are electrically connected to circuits on the circuit board adjacent to and in communication with the chip package; and
a connector that includes a body that supports a pair of signal terminals and a ground terminal in a row, the pair of signal terminals each including a contact portion and a tail portion, the tail portions of the pair of signal terminals being connected to the signal conductors of the first cable, the ground terminal including a contact that is positioned adjacent the contacts of the pair of signal terminals and that is connected to the ground shield of the first cable so that the connector and plurality of cables help provide a differential coupled channel between the contacts of the pair of signal terminals and the circuit board.
11. The bypass cable assembly of claim 10 , wherein the row is a first row, the connector includes a second pair of signal terminals and a second ground terminal in a second row, the signal terminals of the second pair of signal terminals each including a contact portion and a tail portion, the tail portions of the second pair of signal terminals being connected to the signal conductors of the second cable, the second ground terminal including a contact that is positioned adjacent the contacts of the second pair of signal terminals and being connected to the ground shield of the second cable.
12. The bypass cable assembly of claim 11 , wherein the bypass cable assembly is configured to support 15 GHz signaling.
13. The bypass cable assembly of claim 11 , wherein the two rows of terminals are each supported by a separate frame that is positioned in the body.
14. The bypass cable assembly of claim 10 , wherein the first pair of signal terminals is arranged so that the pair of signal contacts have ground contacts on both sides of the pair of signal contacts and the ground shield is electrically connected to the ground contacts on both sides of the pair of signal contacts.
15. The bypass cable assembly of claim 14 , wherein a second connector electrically connects the first free end to the circuit board adjacent the chip package.
16. The bypass cable assembly of claim 10 , wherein a second connector electrically connects the first free end to the circuit board adjacent the chip package.
17. The bypass cable assembly of claim 10 , wherein the first cable includes a drain wire.
18. The bypass cable assembly of claim 10 , wherein the row includes a second pair of signal terminals, the first and second pair of signal terminals separated from each other by at least one terminal, wherein each terminal in the second pair of signal terminals includes a contact portion and a tail portion, the tail portions of the second pair of signal terminals connected to the pair of conductors in the second cable, wherein a second ground terminal is positioned adjacent the second pair of signal terminals and the ground shield of the second cable is connected to the second ground terminal.