Datasheet

Data Sheet AD7608
Rev. A | Page 27 of 32
Figure 46 to Figure 52 illustrates the effect of oversampling on
the code spread in a dc histogram plot. As the oversample rate
is increased, the spread of codes is reduced. (In Figure 46 to
Figure 52, AV
CC
= V
DRIVE
= 5 V and the sampling rate was scaled
with OS ratio.)
0
200
400
600
800
1000
1200
1400
1600
–9 –8 –7 –6 –5 –4 –3 –2 –1 0
CODE
1 2 3 4 5 6 7 8 9
3 3
35
82
708
1001
NO OVERSAMPLING
1170
1377
1208
852
588
328
146
66
21
5
0
NUMBER OF OCCURENCES
188
411
08938-044
Figure 46. Histogram of Codes—No OS (18 Codes)
0
200
400
600
800
1000
1400
1800
1200
1600
2000
–8 –7 –6 –5 –4 –3 –2 –1 0
CODE
1 2 3 4 5 6
0
1
15
OVERSAMPLING BY 2
1524
1759
1397
902
498
165
57
9
NUMBER OF OCCURENCES
54
208
08938-045
538
1065
Figure 47. Histogram Of Codes—OS × 2 (14 Codes)
500
0
1000
1500
2000
2500
–5 –4 –3 –2 –1 0
CODE
1 2 3 4 5
OVERSAMPLING BY 4
1551
2224
1913
1072
427
64
14
NUMBER OF OCCURENCES
4
40
08938-046
199
684
Figure 48. Histogram of Codes—OS × 4 (11 Codes)
0
500
1000
1500
2000
2500
3000
3500
–4 –3 –2 –1 0
CODE
1 2 3 4
OVERSAMPLING BY 8
3027
1756
457
44
2
NUMBER OF OCCURENCES
4
78
08938-047
2176
648
Figure 49. Histogram of Codes—OS × 8 (9 Codes)
OVERSAMPLING BY 16
0
500
1000
1500
2000
3000
4000
2500
3500
4500
–2 –1 0
CODE
1 32
3947
385
2703
7
NUMBER OF OCCURENCES
08938-148
1081
69
Figure 50. Histogram of Codes—OS × 16 (6 Codes)
OVERSAMPLING BY 32
0
1000
2000
3000
4000
5000
6000
–2 –1 0
CODE
1 2
5403
17
1460
NUMBER OF OCCURENCES
08938-149
1301
11
Figure 51. Histogram of Codes—OS × 32 (5 Codes)