# sampling rate and bit resolution for Scanning Probe Microscopy

I am trying to compare two products and see which one offers higher performance in terms of sampling rate and bit resolution.

Below are the specs I was able to gather from product1 and product 2. (I am not sure if I am looking at the relevant specs though.)

Product 1:
Input: ADC @ 400 kS/s, 18 bit
2 HF ADC inputs @ 50 MS/s, 16 bit
Output: DAC outputs @ 200 kS/s, 16 bit

Product 2:
Input: 20-bit @ 60 kS/s, 22-bit @ 1 kS/s (oversampling)
Output: 20-bit, 1-ppm precision, 1 MS/s

I think it's true that higher resolution in bits is going to result in better performance. However, it seems product 1 has a higher sampling rate.

Could someone tell me which product will result in finer resolution in both input and output and why?

• Do you want resolution in time or resolution in voltage? They're two independent parameters. – Dave Tweed Mar 16 '19 at 15:28
• Clarify what you mean by "resolution in input" and "resolution in output". Those are nonsensical terms. – TimWescott Mar 16 '19 at 15:30
• @TimWescott My apologies. I meant the size of each step when the measured analog signal gets converted into a series of steps by 'resolution in input' (ADC)and the size of each step when I order the box to ramp a voltage from 0 to 10V (DAC) for example. – Blackwidow Mar 16 '19 at 15:39
• @DaveTweed Ideally, I would like to pick a product that is superior in both regards. – Blackwidow Mar 16 '19 at 15:39
• Well, neither of your options are better in both regards than the other. Product 1 has a better time resolution, and product 2 has a better voltage resolution. – Hearth Mar 16 '19 at 15:45