Hi,
with reference to the attached schematic, I need to minimise noise picked up by the 3 meters long cable. Noise can be picked up by the cable and fed back into the driving (instrumentation) amplifier which in turns is amplified in its output. According to Fig 19 Page 8 of the attached application note, when driving long cables, you can use a resistor in series with a ferrite bead on the instrumentation amplifier output to reduce that issue.
Three questions:
1) is resistor required? why and how do you choose the value?
2) I am thinking of putting one also in the input (i.e. receiving side op-amp input). Is that correct? How do I choose the value for this one? Based on the op-amp input impedance maybe? How?
3) if the cable is both shielded and twisted pair, is the ferrite still required? In other words, is it worth putting it in or not for a 3 meters long cable?
Many thanks all feedback
with reference to the attached schematic, I need to minimise noise picked up by the 3 meters long cable. Noise can be picked up by the cable and fed back into the driving (instrumentation) amplifier which in turns is amplified in its output. According to Fig 19 Page 8 of the attached application note, when driving long cables, you can use a resistor in series with a ferrite bead on the instrumentation amplifier output to reduce that issue.
Three questions:
1) is resistor required? why and how do you choose the value?
2) I am thinking of putting one also in the input (i.e. receiving side op-amp input). Is that correct? How do I choose the value for this one? Based on the op-amp input impedance maybe? How?
3) if the cable is both shielded and twisted pair, is the ferrite still required? In other words, is it worth putting it in or not for a 3 meters long cable?
Many thanks all feedback
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