Datasheet

AD7986
Rev. B | Page 10 of 28
0 200k 400k 600k 800k 1M
–180
–200
–160
–140
–120
–100
–80
–60
–40
–20
0
FREQUENCY (Hz)
AMPLITUDE (dB)
07956-111
f
S
= 2MSPS
f
IN
= 20kHz
SNR = 97.0dB
THD = –114.0dB
SINAD = 97.0dB
Figure 11. FFT Plot (External Reference)
14
15
16
17
18
80
85
90
95
100
2.5 3.0 3.5 4.0 4.5 5.0
ENOB (Bits)
SNR, SINAD (dB)
REFERENCEVOLTAGE (V)
SNR
SINAD
ENOB
07956-212
Figure 12. SNR, SINAD, and ENOB vs. Reference Voltage
80
85
90
95
100
1k 10k 100k 1M
SINAD (dB)
FREQUENCY (Hz)
07956-013
Figure 13. SINAD vs. Frequency
0 200k 400k 600k 800k 1M
–180
–160
–140
–120
–100
–80
–60
–40
–20
0
FREQUENCY (Hz)
AMPLITUDE (dB)
07956-114
f
S
= 2MSPS
f
IN
= 20kHz
SNR = 95.5dB
THD = –113.0dB
SINAD = 95.5dB
Figure 14. FFT Plot (Internal Reference)
105
110
95
100
115
120
125
–120
–125
–115
–110
–105
–100
–95
2.5 3.
0 3.5 4.0 4.5 5.0
SFDR (dB)
THD (dB)
REFERENCE VOLTAGE (V)
THD
SFDR
07956-015
Figure 15. THD and SFDR vs. Reference Voltage
–125
–120
–115
–110
–105
–100
–95
–90
–85
–80
1k 10k 100k 1M
THD (dB)
FREQUENCY (Hz)
07956-216
Figure 16. THD vs. Frequency