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TheAnalogKid83
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I have what seems like a simple problem. I was asked to use a simple resistor divider as a scaling circuit into an A/D converter. My problem is that I have a low steady-state current requirement, and so I needed to increase the resistor values. I was told this is not an option because it causes the circuit to be susceptible for EMC. I don't want to exceed 100uA, and preferably would be down to about 10uA in my current draw for this scaler. The only idea I've been able to think of as a replacement design is to use some op amp stages, hoping I can get away with larger resistor values in the -R2/R1 gain divider since the opamp is an active device. Is this foolish to think an opamp would help cut down the current draw without being more susceptible? I'll be doing spice simulations and circuit analysis, but I'm not sure how to calculate for and simulate electromagnetic interference (assume a noise signal superimposed on my input signal? but its not just on the input signal, its being applied to the entire circuit). Does anyone know much about this?
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