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Adding another high speed ADC

Posted: Mon Jan 25, 2021 1:55 am
by elevon
Hi!

I would like to make a small shield to add another LTC2145.

But there are only 16 digital I/O pins on the board. Fortunately the A/D chips can operate in a double data rate mode.
Each data I/O pin would then update its value up to 250 times per second in single ended mode.
Would that rate still be acceptable for the extension connector pins?

Also, the schematic states that those are 3.3 V pins.
The high from the data pins of the ADC will be 1.8 V. Is this high enough to be detected as such by the I/O-pin?

Thank you!

Re: Adding another high speed ADC

Posted: Thu Mar 18, 2021 10:27 am
by redpitaya
1.8V - probably should not work.

under 0.8V is a low and over 2V is a high according to our documentation
https://redpitaya.readthedocs.io/en/lat ... 20analizer

But you can try it if you can.