Datasheet

AD7606/AD7606-6/AD7606-4 Data Sheet
Rev. C | Page 30 of 36
Figure 49 to Figure 55 illustrate the effect of oversampling on
the code spread in a dc histogram plot. As the oversample rate
is increased, the spread of the codes is reduced.
1000
0
100
200
300
400
500
600
700
800
900
NUMBER OF OCCURENCES
CODE (LSB)
–3 –2 –1 0 1
928
887
3
0 3 2
2
131
97
08479-047
NO OVERSAMPLING
F
SAMPLE
= 200kSPS
AV
CC
= 5V
V
DRIVE
= 2.5V
Figure 49. Histogram of Codes—No OS (Six Codes)
1400
0
200
400
600
1000
1200
800
NUMBER OF OCCURENCES
CODE (LSB)
–3 –2 –1 0 1 3
0 0 0
2
16
08479-048
OVERSAMPLING BY 2
F
SAMPLE
= 100kSPS
AV
CC
= 5V
V
DRIVE
= 2.5V
80
804
1148
Figure 50. Histogram of Codes—OS × 2 (Four Codes)
1400
0
200
400
600
1000
1200
800
NUMBER OF OCCURENCES
CODE (LSB)
–3 –2 –1 0 1 3
0 0 0
2
3
08479-049
OVERSAMPLING BY 4
F
SAMPLE
= 50kSPS
AV
CC
= 5V
V
DRIVE
= 2.5V
19
764
1262
Figure 51. Histogram of Codes—OS × 4 (Four Codes)
1400
0
200
400
600
1000
1200
800
NUMBER OF OCCURENCES
CODE (LSB)
–3 –2 –1 0 1 3
0 0 0
2
0
08479-050
OVERSAMPLING BY 8
F
SAMPLE
= 25kSPS
AV
CC
= 5V
V
DRIVE
= 2.5V
2
783
1263
Figure 52. Histogram of Codes—OS × 8 (Three Codes)
1400
0
200
400
600
1000
1200
800
NUMBER OF OCCURENCES
CODE (LSB)
–3 –2 –1 0 1 3
0 0 0
2
0
08479-151
OVERSAMPLING BY 16
F
SAMPLE
= 12.5kSPS
AV
CC
= 5V
V
DRIVE
= 2.5V
0
595
1453
Figure 53. Histogram of Codes—OS × 16 (Two Codes)
1600
1400
0
200
400
600
1000
1200
800
NUMBER OF OCCURENCES
CODE (LSB)
–3 –2 –1 0 1 3
0 0 0
2
0
08479-152
OVERSAMPLING BY 32
F
SAMPLE
= 6.125kSPS
AV
CC
= 5V
V
DRIVE
= 2.5V
0
631
1417
Figure 54. Histogram of Codes—OS × 32 (Two Codes)
1600
1400
0
200
400
600
1000
1200
800
NUMBER OF OCCURENCES
CODE (LSB)
–3 –2 –1 0 1 3
0 0 0
2
0
08479-153
OVERSAMPLING BY 64
F
SAMPLE
= 3kSPS
AV
CC
= 5V
V
DRIVE
= 2.5V
0
1679
369
Figure 55. Histogram of Codes—OS × 64 (Two Codes)