Improving signal integrity in differential signal systems
AssigneeHewlett-Packard Development Company, L.P.
InventorsChi Kim Sides, Sompong Paul Olarig
Life of this patent
Estimating the term…
Abstract
Over-terminating the differential mode impedance of a differential transmission line, such as an INFINIBAND™ cable, at the receiving end, improves the differential signal integrity for typical variations in termination network impedance component (e.g., resistor) and transmission line characteristics. Eye opening of the differential signal can be made larger with reduced attenuation but increased jitter compared to under-terminating the differential mode impedance. Because the differential signal quality (larger eye opening) is improved, data can be transmitted over a longer transmission line with the same transmitter and receiver.
Claims29
A method for improving differential signal integrity in a transmission line system, the method comprising:
- propagating a differential signal on a transmission line;
- and
- over-terminating the differential signal at a termination network, wherein the over-terminating comprises terminating the differential signal such that less attenuation but more jitter results compared to perfect impedance matching of the differential signal when performing eye opening tests on the transmission line.
An apparatus for improving high-speed differential signal integrity in a
- transmission line system, comprising:
- a transmission line;
- and
- a termination network coupled to the transmission line and adapted to over-terminate a differential mode of the transmission line, wherein the termination network is adapted to terminate the differential signal such that less attenuation but more jitter results compared to perfect impedance matching of the differential signal when an eye opening test is performed on the transmission line.
An apparatus for improving high-speed differential signal integrity in a transmission line system, comprising:
- a transmission line;
- and
- a termination network coupled to the transmission line and adapted to over-terminate a differential mode of the transmission line, wherein the over-termination is less than or equal to approximately 20% over perfect impedance matching of the differential mode of the transmission line.
Dependencies are inferred from the claim text.