SNR of AD7768-1 with AD8250 at 48 kHz input frequency

hi Niels

check out the precision driver tool https://tools.analog.com/en/precisionstudio/

it has LTC6363 and AD7768 combination with the noise calculation

Hope it helps

This is a nice tool, but how do I add the AD8250?

Are there any other means to add the influence of the AD8250?

Hi Niels 

to maximise SNR noise needs to be low, i would suggest this Inamp which has more gain options that are digitally controlled  and has better noise numbers

https://www.analog.com/en/products/ltc6373.html

thanks

Wa$iM,

thanks for indicating the LTC6373, a great device.
But why didn't you add a gain of 0.2?
This would allow using it directly with ADCs that have a 4.096V reference.

Unfortunately, Precision Studio does not support SNR calculation for the LTC6373 or AD8250.

Again: How could I predict the influence of the AD8250/LTC6373 on total SNR?

Regards, Niels

Hi Niels

You can do a RMS to calculate the overall noise.

so from tool you got the system Noise of LTC6363-05 + AD7768-1 @ 32ksps to be 4.57uVrms

LTC6373 noise @ G=1 is 18.7nV/sqrt Hz..@ 32ksps FIR BW is about 14kHz.

So 18.7*sqrt(14k) = 2.2uV.. so total noise is sqrt(2.2*2.2 + 4.57*4.57) = 5uV

coming to gain options .. +/-10V signal with 0.5 gain = +/-5V signal @ LTC6373 output and you can always use 5V reference

thanks