HI
We use the AD9142A (great chip) and AD9783
We want to use the AD9142A in a mix mode (invert ever other output sample) and as independent DACs (like the 9783)
However ! the minimum x2 upsampling HB filter in the signal chain prevents this. I have a couple of ideas :
1) We could run the NCO FTW at exactly DACCLK/2. This would mean the NCO cosine output was 1,-1,1,-1 and the sine output stays zero, this would then multiple the output by 1, -1 etc and the sine output that stays zero would mean there was no additon/ mix between the NCO / DAC chains .
If not familiar, see figure 47 of the datasheet Figure 47. NCO Modulator Block Diagram....
what do you think? as the NCO is clocked at FDAC, this should work....
2) Is there any way to write to the half band filter coefficients ???
with thanks
Glen
