Hello guys,

I have implemented an ideal ADC+DAC converter and I did an FFT analysis. I did a test with coherent sampling with rectangular window and everything was ok. Input freq. 1,376...MHz, 500mV, sinewave and a starting phase of -90º. That gave Me 7,96bits (8bits ideal).

Then I changed the phase to -60º and rectangular window and gave me SINAD = 43,77 dB e ENOB = 6,98 bits. Then I used hanning window with a phase -60º and the ENOB gave Me a very strange value: SINAD = - 0,34 dB e ENOB = - 0,35 bits.

Can someone tell Me way? Don't understand that strange value.

Kind regads.