Thermocouple signal conditioning - how to deal with low output swing margin of amplifier?
I have this thermocouple conditioning circuit. Let's say my gain is 100. Minimum low level for AD8237 is 20mV. As K type thermocouple outputs 40uV per 1C, I will have 4mV per 1 degree C.
This means I will not see change on the output while temperature goes from ambient to ambient + 5C.
Suppose, I don't want to loose these 5 degrees at the bottom of my range. What do I do? I think, I have to inject some offset into the +IN input? If so, how do I do it? What are the other possibilities?
I would like to avoid using split supply.
I have this thermocouple conditioning circuit. Let's say my gain is 100. Minimum low level for AD8237 is 20mV. As K type thermocouple outputs 40uV per 1C, I will have 4mV per 1 degree C.
This means I will not see change on the output while temperature goes from ambient to ambient + 5C.
Suppose, I don't want to loose these 5 degrees at the bottom of my range. What do I do? I think, I have to inject some offset into the +IN input? If so, how do I do it? What are the other possibilities?
I would like to avoid using split supply.
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