Hello team.
I am trying to the combo tdc1000 & tdc7200 for water flow meter.
Beacause I have the chips and I want to test it.
Could you please instruct if I should ground or shortcut the pins, if I don't want to use them:
LNAOUT - PGAIN (Shortcut)
PFAOUT - COMPIN (Shortcut)
RTD1 , RTD2 grounded
Best regards
Manos
Hello Manos,
Thank you for your question. In the case of RTD1 and RTD2, if you do not plan on using a temperature sensor you may leave those pins open and set MEAS_MODE to 0. Typically for LNAOUT -> PGAIN & PGAOUT -> COMPIN, you can use external circuits in these points in order to optimize your set up to yield the best results possible. For example in our TDC1000-C2000EVM User's Guide you can see the schematic to view an example of this. You can see the screenshot below (found on page 19):
The circuit between LNAOUT and PGAIN serves as an external High Pass filter. The circuit between PGAOUT and COMPIN serves as an external Low Pass filter. So while it may very well be connected directly like as you mentioned, it may prove useful to test first without these external circuits and see if you no further filtering is required.
Best,
Isaac
