www.ti.com
10
1
0.1
THD+N(%)
0.01
0.001
20
100
1k
Frequency (Hz)
10k 20k
Left
Right
4.3.1
FFT Spectrum with –60dBFS Tone
0
-
10
-
20
-
30
-
40
-
50
-
60
-
70
-
80
-
90
-
100
-
110
-
120
-
130
-
140
-
150
OutputV
oltage(dBrA)
0
2k
Frequency (Hz)
22k
4k
6k
8k
10k 12k 14k 16k 18k 20k
DRV600EVM Performance
The DRV600EVM uses a 1
μ
F film capacitor for ac-coupling of the input signal. If a lower cost ceramic
capacitor such as an X7R is used, higher THD at low frequencies should be expected. Y5V capacitors will
show even higher THD performance and should not be used.
Figure 8. THD+N vs Frequency (600
Ω
load) Using X7R Input Caps
The X7R capacitors raises the 20Hz THD from 0.02% to 0.1%—five times higher.
Reference voltage is 2V
RMS
, FFT size 16k.
Figure 9. FFT Spectrum with –60dBFS Tone
This spectrum corresponds to a dynamic range of 110dB, A-weighted. SNR measures at 110dB,
A-weighted.
DRV600EVM User's Guide
8
SLOU205 – July 2007
