Routing Consideration; Figure 11 Sdvo To Dvi Transmitter Example (Part 1) - Emerson COM Express Carrier Design Manual

Figure 10 SDVO to DVI Transmitter Example (Part 1)

4.3 Routing Consideration

The PEG and general PCI Express routing requirement is the same as described in Chapter 3.
The digital video interface (DVI) is based on the differential signaling method TDMS. To achieve the full
performance and reliability of DVI, the TDMS differential signals between the SDVO-to-DVI transmitter
and the DVI connector have to be routed in pairs with differential impedance of 100 ohms. The length
of the differential signals must be kept as close to the same as possible. The maximum length
difference must not exceed 100 mils for any of the pairs relative to each other. Spacing between the
differential pair traces should be more than two times the trace width to reduce trace-to-trace
couplings. For example, having wider gaps between differential pair DVI traces will minimize noise
coupling. It is also strongly advised that ground should not be adjacent to the DVI traces on the same
layer. There should be a minimum distance of 30 mils between the DVI trace and any ground on the
same layer. For more information, refer to the layout and routing considerations as specified by the
manufacturer of the SDVO-to-DVI transmitter.
COM Express Carrier Type 2
Design Guide
Page 35 of 103