Cabling Solution for Analog Differential Line

[zdavis92]

Hi Al (first post on this site!)

I'm designing a system with 2 different PCBs. First PCB has a THS4140 used to convert a single-ended analog signal to a differential signal. Second PCB has an ADC with differential input This differential signal needs to find its way to an ADC on the second board, via some sort of cable. I included a reference snapshot, in attachments, from the datasheet of the THS4140 in case you want a better visualization.

I was wondering if you had suggestions on which cabling solution might fit my needs? Was thinking some sort of twinax or twisted pair, but not sure if anyone has any better suggestions.

All input appreciated. Thanks!

[zdavis92]

Thanks for reply.

The bandwidth is pretty low, below 80 MHz. Most worried about EMI radiating from digital electronics inside the contraption this will be in (will be inside a piece of test equipment). The analog line comes from a low level analog sensor used to take very sensitive measurements, so we are primarily focused on shielding these lines from any noise. Primarily chose differential mode of transmission to suppress any common mode noise picked up on cable. The distance it's going over is about 1 meter, so was hoping to use a shielded twisted pair or shielded differential transmission line. Do you think just using standard SMA/BNC and single ended would work for this?

[David Hess]

4 wire ribbon cable with the two outside wires being ground will also work.

An inexpensive solution if you want shielded cable is microphone cable.  Twisted pair with a foil shield and drain is also available.