Other Parts Discussed in Thread: THS4551, REF5045
e2e,
I am currently working on a proof of concept board for NASA that focuses on low noise (<.1mV) low frequency signals (.01 - 100 Hz). In our current design the preferred signal to digitize and communicate via SPI a +- 5V AC signal operating near DC frequencies. We are currently using the ADS8924B, however, it would require a schematic rework to fit the full signal into the 0 - 5V range since this is an unipolar ADC.
From here the only solution I see outside of a rework (correct me if I am wrong please) is to find another precision ADC that accepts a bipolar differential input range of +- 5V and communicates using SPI. I have combed through the internet trying to find an ADC that fits these signal input specs and doesn't suffer with small signals in our frequency ranges.
Other Information:
- Reference Voltage: preferably ground, potentially 2.5V.
- Digital control pins Used: SOMI, MISO, CS, CLK, CONVST, REFBUFOUT.
- Supply voltages: 5V, 2.5V, -5V.
- Side Note: as this is a proof of concept the ADC does not need to be military/space grade for this application.
Your help is much appreciated,
-Karl texasinnovation@gmail.com