Datasheet

AD7666
Rev. 0 | Page 13 of 28
03034-0-011
0
20000
40000
60000
80000
100000
120000
COUNTS
7FFE 7FFF 8000 8001 8002 80037FFD 8004
CODE IN HEX
7FFC
0
211
623
4
20187
15968
1
112335
111791
0
Figure 11. Histogram of 261,120 Conversions of a
DC Input at the Code Transition
03034-0-012
–180
–160
–140
–120
–100
–80
–60
–40
–20
0
AMPLITUDE (dB of Full Scale)
0 50 100 150 200 250
FREQUENCY (kHz)
f
S
= 500kSPS
f
IN
= 101.361kHz
SNR = 88.6dB
THD = –98.1dB
SFDR = 99.2dB
S/[N+D] = 88.1dB
Figure 12. FFT Plot
03034-0-013
SNR
S/[N+D]
ENOB
81
82
83
84
85
86
87
88
89
90
91
SNR, S/[N+D] (dB)
1 10 100 1000
FREQUENCY (kHz)
13.0
13.5
14.0
14.5
15.0
15.5
ENOB (Bits)
Figure 13. SNR, S/(N+D), and ENOB vs. Frequency
03034-0-014
0
11
2789
3300
34
0
0
20000
40000
60000
80000
100000
120000
140000
160000
180000
COUNTS
CODE IN HEX
7FFA 7FFB 7FFC 7FFD 7FFE 7FFF 8000 8001 8002
148481
53814
52691
Figure 14. Histogram of 261,120 Conversions of a
DC Input at the Code Center
03034-0-015
SFDR
THD
SECOND
HARMONIC
THIRD
HARMONIC
–120
–115
–110
–105
–100
–95
–90
–85
–80
–75
–70
THD, HARMONICS (dB)
1 10 100 1000
FREQUENCY (kHz)
20
30
40
50
60
70
80
90
100
110
120
SFDR (dB)
Figure 15. THD, Harmonics, and SFDR vs. Frequency
03034-0-016
88
89
90
91
–60
–50 –40 –30 –20 –10 0
INPUT LEVEL (dB)
SNR, S/[N+D] REFERRED TO FULL-SCALE (dB)
SNR
S/[N+D]
Figure 16. SNR and S/(N+D) vs. Input Level (Referred to Full Scale)