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

Amplitude — dB
–20
–40
–60
–80
–100
–120
–130
Figure 14–6. Total Harmonic Distortion
20
0
Fundamental
F
Harmonics
H2 H3 H4 H5 H6 H7 H8 H9
0 1 k 2 k 3 k 4 k 5 k 6 k 7 k 8 k
Frequency – Hz
D/A Converter Error Budget
9 k 10 k
Assuming ideal D/A conversion, there is a direct relationship between the number of bits
and the THD caused by the resolution:
14.4.3.2 Dynamic Range
THD(%) 1
100
2N Interfacing D/A Converters to Loads
(14–2)
Where N is the number of converter bits. Of course, this is the limit for ideal conversion.
There is also a direct relationship between the number of bits (n) and the maximum dynamic
range of the D/A (Equation 14–2 and Table 14–2):
Dynamic Range 6.02 n 1.76
(14–3)
Notice that there is approximately a 6-dB improvement in dynamic range per bit. This is
an easy way to figure out what improvement can be realized by increasing the number
of bits from one value to another.
14-9