inquiry about the LSB of the Discovery 3

[mohamed.mo99]

hello all,

so it's said that the scope in the analog discovery 3 has +-25V full scale and 14 bit resolution so my question is about calculating the LSB. would it be the full scale / 2^14 which in this case would be 50/2^14 which gives around 3mV but in the scope you can adjust the voltage per division to as low as 200uV per division so in that case the full scale to calculate the LSB would be different, correct?

[artvvb]

Hi @mohamed.mo99

Apologies for the delay.

Per the spec sheet, the AD3's absolute resolution is 0.336 mV and 3.36 mV in the two hardware ranges (WaveForms picks which range to use based on the Range setting in the app). These values are based on full ranges of 5.5 V and 55 V (55 V / 2^14 = 3.36 mV). I believe the extra padding in the full ranges ensures that component differences between units don't prevent a specific unit from being able to cover the full +-25 V range, and for other hardware design reasons that I don't have all the details on.

You might find the AD2's hardware design guide interesting. Different device, but it's fairly similar to the AD3 overall.

Thanks,

Arthur