Rafael Del Rey Acuna

RX-TX Pokayoke

Discussion created by Rafael Del Rey Acuna Employee on Feb 18, 2014

Sometimes, RX-TX transceiver interconnections aren’t well defined about who is the module that transmits or receives. This is due to lags in design requirements or information missing.


Proposed strategy consists in including a couple of series resistors in the TX and RX nets as shunts. These resistors might also work also as current limiters. 0603 size was used for this strategy.




The resistor shunts will provide a platform to intercross RX to TX connections by rotating these resistors 90 degrees in a rework.


For this reason one of these resistors should rotate 180 degrees in layout, and both resistors should be placed one besides the other, maintaining same air gap between resistors’ pads, therefore, preserving its schematic connections.




CAD should look similar to this:


As a final result, in case of misconnection, a quick rework consisting in 90 degrees resistors’ rotation will fix the issue.