Ok her is final solution.
1. Effect of DAC Resolution
DAC resolution make quantization distorsion (quantization error)
B is DAC resolution
for 10 bit DAC SQR= 61.96 dB
for 12 bit DAC SQR= 74.00 dB
for use full DAC resolution
2. effect of reduction full scale DAC
if not used ful scale DAC
Code:
SQR=1.76+6,02B + 20log(FFS) (dB)
for exmple if use only 70% full resolution DAC FFS=0.7
for 10 bit DAC SQR= 58.86 dB
for 12 bit DAC SQR= 70.90 dB
for use 70% DAC resolution
3. Effect of oversamplign i.e sample rate DAC
Code:
SQR=1.76+6,02B + 20log(FFS) + 10log(FSos/Fs) (dB)
Where Fs is the Nyquist sampling rate and FsOS is the oversampling rate.
for exmple output freuency Fo=100kHz, FS=2*Fo, for 1MSPS DAC FSos=1MHz oversampling 5x
for 10 bit DAC SQR= 68.95 dB
for 12 bit DAC SQR= 80.99 dB
for use 100% DAC resolution