I have read most of what I could find about the AD5940 or ADuCM355, including datasheets, other questions from this forum and the GitHub page of the library for this parts, but still couldn't fully understand this:
Can this parts be used to interface with one 4-lead electrochemical amperometric gas sensor with reference, counter, sensing (working) and aux electrodes?
As an example, the Alphasensens B4 line of sensors for CO, H2S, SO2, etc all have an auxiliary 4th electrode that shares the same RE and CE of the sensing electrode. The aux electrode is shielded from the target gas, and is only affected by ambient conditions such as temperature. So the purpose of the aux electrode is to help correct the influence of temperature in the sensing electrodes reading. This is an example of the circuit used for those sensors:
From what I could understand so far, the only way of using AD5940 in this configuration would be to use the low power TIA with the sensing electrode and use the high speed TIA with the aux electrode connected to the DE pin. Is that correct? With the HSTIA I wouldn't have the capacitor to help filter the noise from the sensor, right? Would it be possible to use the LPTIA for both aux and sensing? Would I have more options if I used ADuCM355 (one more channel) instead?
Thank you in advance!