"Chapter 1 - The Op Amp's Place in the World" - HTL Wien 10

14.5.2.4 Spurious Free Dynamic Range
D/A Converter Errors and Parameters
Spurious free dynamic range is the difference in dB between the maximum signal component
and the largest distortion component (Figure 114–11):
Amplitude — dB
20
0
–20
–40
–60
–80
–100
–120
–130
Fundamental — F
SFDR
Figure 14–11. Spurious Free Dynamic Range
0 1 k 2 k 3 k 4 k 5 k 6 k 7 k 8 k
Frequency – Hz
9 k 10 k
It is an important specification in RF applications, where FCC regulations specify the magnitude
of spurs.
Improper decoupling may cause spurs. A notch filter can be used to eliminate a spur, but
many RF applications are RF agile — changing the frequency of the spur as well. The
notch must catch all spur frequencies, or it is useless.
14.5.2.5 Intermodulation Distortion
The differential and integral nonlinearity errors described previously appear in a high-frequency
ac application as intermodulation distortion (Figure 14–12).
Interfacing D/A Converters to Loads
14-15