I'm having difficulty finding a suitable cable for a wired sensor applicati on, and I was wondering if anyone could check my design approach. Basicall y, my control circuit powers a wired sensor located about 2 meters away. T he sensor circuit uses a single-ended op-amp to amplify a 5 MHz transducer signal, and then sends it back to the control circuit where it is digitized . So, I need 3 wires between the control circuit and the sensor: Vcc, gro und, and signal.
Since the cables from multiple sensors will be running next to each other, I thought I should use twisted-triad wire to reduce cross-talk. External E MI shouldn't be a problem, so I don't think shielded cables are necessary. However, I haven't been able to find twisted-triad wire without a jacket o r shield. What kind of wire should I use for this? If I used two twisted- pair wires for each sensor, what would I connect the extra wire to?
The sensor has a Vcc bypass capacitor, so I think most of the higher freque ncy content will be between signal and ground. Since I'm bringing back the signal and ground wires together, would this be considered a balanced circ uit?
Thanks, Doug