I'm interested in using the AD9910's inverse sinc filter, and I was wondering if it makes sense to try to use its auxiliary DAC to compensate for the filter's ~3 dB insertion loss.

In terms of the current output of the main DAC, am I right in thinking that this 3 dB loss would reduce Iout by a factor of sqrt(2)? If so, would it be valid to adjust the value of the CODE (aka FSC) parameter in the equation below as needed to compensate for this reduction?

So for example, if the inverse since filter would reduce Iout by a factor of sqrt(2), then using Rset = 10k and setting CODE = 219 would give Iout = 20.05 mA.

Is this valid, and if so, is it recommended?

Hi DZF,

I've heard some applications that uses the method that you are proposing. So for me, that is highly feasible. You can program your controller such that it would control the DAC current depending on what frequency you are using. The attenuation behavior is predictable so you can assign gain coefficients( DAC code) to further correct the sinc behavior.

Thanks

Louijie