Did not work in what way? The voltage was not attenuated? It was attenuated, but by the incorrect amount? You got zero signal?
Originally it just gave me complete nonsense so I switched to a different power supply and now it works.
There are a couple of "funny" things about that... It's differential and the ADC seems to have a "known" high impedance which is being used as part of the voltage divider. (You are using a different ADC.)
Your ADC is also differential, but is your source differential? What's the impedance of your source?
In this case, my source is does not have a differential input. What I would like to try however is make use of the common mode to offset the sampling range.( If id didn't misunderstand how this works)
Unfortunately I don't have the input impedance right now but Ill try to make it available as soon as possible.
If your signal is differential, you can make your own differential voltage divider with 3 resistors. That's 3 resistors in series with the balanced output coming off the middle resistor. The top & bottom resistors should be the same and the attenuation is the middle resistance to the total resistance.
Would this still make sense when using the ADC with a single signal input (other one is connected to ground)
It will not increase the noise.
You could a,ways use an op-amp with a gain of 0.5
Would using an op-amp in this case have advantages?
Too large resistance values will add Johnson noise, whether this matters depends on your noise bandwidth,
so you have to figure that out - basically if your signal of interest has a particular bandwidth it always
pays to low-pass filter and remove noise at higher frequencies. And of course you'll probably need an anti
aliasing filter anyway.
Too large resistance values will act as a low-pass filter anyway, so you really need to know what
your source impedance, desired bandwidth and accuracy are.
Right now I tried tripling my range so I used 750kohm resistors in combination with the 350kohm
internal resistance of the ADC. That did work, and I am using capacitors to filter the noise.
Do you think the resistance is unusually high?
What do you guys think would be the best solution?
-The voltage divider to ground.
-The voltage divider in relation to the adc's internal resistance?
-Would I still be able to offset the input range by by connecting -ve to a different voltage?
Thank you all for your responses.