I need to transmit several analog signals from one board to another (maximum 1m distance) in a very noisy environment (power electronics converter operating at 20kHz). The range of frequencies of the analog signals is [0,20 MHz]. Presently I opted for differential signals, and designed a differential driver AD8132 on the transmit side. The signal from the sensor is 300mV p-p (current shunt if it matters). On the receiver side, I am using a difference amplifier AD8270. I expect this to do sufficiently well since the common mode signal will be small (grounds of both boards are tied at single point) The circuit is illustrated in the image below (i simulated it in spice with different components earlier but the circuit layout is the same. In the meantime i changed the amplifiers but the functionality should stay the same). I opted for simple difference amplifier. The rationale is that the common mode voltage is expected to be low which in combination with matched resistor network of AD8270 should give decent performance.I plan to use a twisted pair to transmit the signals.
- Should I be worried about reflections on the cable?
- Would a coaxial cable be a better/simpler solution in this situation?
Any thoughts/suggestions are appreciated.