Description:
A designer would like some indication of the level of SSO noise he might see from BLVDS IOs, but the SSO Calculator in ispLever does not support the BLVDS IO type.
Solution:
The SSO Calculator estimates SSO noise for single ended fully switched IO types such as LVCMOS driving capacitive loads. In contrast, the BLVDS output type has resistive loading in a differential output configuration with short traces to the resistor source terminations and is not supported by the SSO Calculator in ispLever.
If a designer wants to have a rough estimate of the BLVDS SSO noise contribution, a simple approximation could be to run the SSO Calculator with the BLVDS IOs changed to LVCMOS25 IOs with 8ma drive level and then for each output load, enter 3.5pF per inch of signal trace between the output IO to the source termination resistors.