Other Parts Discussed in Thread: SN74CB3T3257, , SN74CB3Q3257, SN74CBTLV3257
Hello,
As part of an LVDS video control circuit, there are two RGB video data streams being multiplexed through an SN74CB3T3257 into a DS90CF363B.
When probing these signals using Tektronix TAP3500 active probes, it is observed that for signals with long logic high hold times (HSYNC, VSYNC, DE) the output voltage of the SN74CB3T3257 droops from 3.3V down to 2.2V even while the input sustains a constant 3.3V level.
There are no additional components between the two ICs, only copper, and a first look at the impedances of the output and input do not indicate any obvious explanation to this behavior. If anyone has any additional background working with these components or an explanation for this behavior that has slipped my mind I would greatly appreciate it. Of note, performance of the LVDS multiplexing is fine and not compromised in any way, this is merely a due diligence investigation into the anomalous behavior.
