TY - GEN
T1 - Effect of nanosecond electrical discontinuities in high-speed digital applications
AU - Smith, S. B.
AU - Balasubramanian, V.
AU - Nardone, D.
AU - Agili, S. S.
PY - 2008
Y1 - 2008
N2 - Nanosecond discontinuities are a concern in separable-interface connectors. Speculation about their causes includes the structural movement between perfectly clean and flat contact surfaces and/or surface irregularities and presence of surface films. Both of these scenarios are considered here in the context of high-speed transmission (i.e. greater than 1 Gbit/s) in backplane connectors. Because such connectors have gold-to-gold mating surfaces, oxide-related discontinuities such as may occur with tin, silver, or aluminum interfaces are not considered. This paper considers the propagation speed of a stress wave to show the unlikelihood of nanosecond discontinuities arising due only to macroscopic structural shock and vibration. Thus, contact physics and the presence of contact imperfections, are required to cause nanosecond-level intermittences. Assuming that a discontinuity of one or several nanoseconds does occur, the short duration of the event permits only a minute separation between the two contact surfaces. This effect is equivalent to and modeled as the insertion of a very large series capacitor between the two conductors. At high frequencies, such a capacitor would behave quite similarly to a short circuit. Circuit simulations of a communication link and the resultant insertion loss and eye patterns show that these discontinuities do not disrupt high-speed data transmission.
AB - Nanosecond discontinuities are a concern in separable-interface connectors. Speculation about their causes includes the structural movement between perfectly clean and flat contact surfaces and/or surface irregularities and presence of surface films. Both of these scenarios are considered here in the context of high-speed transmission (i.e. greater than 1 Gbit/s) in backplane connectors. Because such connectors have gold-to-gold mating surfaces, oxide-related discontinuities such as may occur with tin, silver, or aluminum interfaces are not considered. This paper considers the propagation speed of a stress wave to show the unlikelihood of nanosecond discontinuities arising due only to macroscopic structural shock and vibration. Thus, contact physics and the presence of contact imperfections, are required to cause nanosecond-level intermittences. Assuming that a discontinuity of one or several nanoseconds does occur, the short duration of the event permits only a minute separation between the two contact surfaces. This effect is equivalent to and modeled as the insertion of a very large series capacitor between the two conductors. At high frequencies, such a capacitor would behave quite similarly to a short circuit. Circuit simulations of a communication link and the resultant insertion loss and eye patterns show that these discontinuities do not disrupt high-speed data transmission.
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U2 - 10.1109/HOLM.2008.ECP.21
DO - 10.1109/HOLM.2008.ECP.21
M3 - Conference contribution
AN - SCOPUS:67249100646
SN - 9781424419029
T3 - Electrical Contacts, Proceedings of the Annual Holm Conference on Electrical Contacts
SP - 47
EP - 52
BT - 2008 Proceedings of the 54th IEEE Holm Conference on Electrical Contacts, HOLM 2008
T2 - 54th IEEE Holm Conference on Electrical Contacts, HOLM 2008
Y2 - 27 October 2008 through 29 October 2008
ER -