I have a circuit that is fed into a ADC chip (adc128s022), that I am trying to understand. The sensors are inferred gas sensors. Could you please criticise my analysis.
The way I am reading it:
- Diodes between gnd and signal are for clamping the voltage and protection.
- Inductor , two caps and 200 ohm resister are a low pass filter.
- 10k resister is for further protection.
- Op amp is acting to clamp the voltage 0-5V and for impedance matching?
- The resister and cap after the buffer are another low pass filter. Is this because the buffer could amplify some small amplitude signal noise?
I am not sure what the point is of the first capacitor, may be to protect the sensor?
I am guessing the different low pass filters before the buffer are for different frequency?