Our customer already had a backplane in service for their multi-card communications system. They wanted to increase the transmission speed on the backplane but were concerned that it might fail.

Context

The customer current backplane had a design that previously had not used its serial channels at high speed. To update their product without having to replace backplanes in the field, the customer requested that we verify that the backplane would be able to operate at a minimum of 3.125 Gbps. Clearly the solution of this problem requires knowledge of high speed digital design and transmission line theory.

Solution

BCA designed some boards to plug into the backplane that had SMA connectors on it and controlled impedance connections. These boards were connected to the backplane and a time domain reflectometer (TDR) device was used to evaluate the various serial interfaces. We identified an IEEE standard for LVDS based serial data interfaces to use as a guideline for evaluation (yes, it was fortunate that we were able to report positive results in this case).