Original question:
ADS1220: Clarification on Effective Resolution of ADS1220 with Internal Reference and PGA Settings
Hi Gabriel,
Looking at your schematic it looks like you are using 2 external MUX's to switch through 8 total thermocouples with the general set-up following Figure 74 in the ADS1220 datasheet.
The only note I would add would be regarding the thermocouple biasing resistors and antialiasing filters. Typical values for the biasing resistors range from 1 MΩ to 10 MΩ. Although the device digital filter attenuates high-frequency components of noise, TI recommends providing a first-order, passive RC filter at the inputs to further improve performance. The filter component values used in the diagram above are: RF1 = RF2 = 1 kΩ, CDIF = 100 nF, and CCM1 = CCM2 = 10 nF.
Overall, the schematic looks to follow the recommended application for the thermocouple measurement and should preform as expected.
How do you plan to measure the cold junction temperature of the thermocouples?
Regards,
Andrew
