Datasheet

Data Sheet AD7791
Rev. A | Page 9 of 20
TYPICAL PERFORMANCE CHARACTERISTICS
04227-0-012
–
120
–
110
–
100
–90
–80
–70
–
60
–
50
–
40
–
30
–
20
–10
0 40
8020
60
100
120
140
dB
160
0
FREQUENCY (Hz)
Figure 6. Frequency Response with 16.6 Hz Update Rate
04227-0-010
0
20
8388591
OCCURENCE
8388619
40
60
80
100
CODE
V
DD
= 3V
V
REF
= 2.048V
9.5Hz UPDATE RATE
T
A
= 25
°C
RMS NOISE = 1µV
Figure 7. Noise Distribution Histogram
(CDIV1 = CDIV0 = 0)
04227-0-011
8388591
0 200 400 600 800
CODE
1000
8388619
READ NO.
V
DD
= 3V, V
REF
= 2.048V, 9.5Hz UPDATE RATE
T
A
= 25°C, RMS NOISE = 1µV
Figure 8. Typical Noise Plot with 16.6 Hz Update Rate
(CDIV1 = CDIV0 = 0)
04227-0-014
0
1
2
3
4
5
6
7
8
8388592
OCCURENCE
8388616
9
CODE
V
DD
= 3V
V
REF
= 2.048V
1.1875Hz UPDATE RATE
T
A
= 25°
C
RMS NOISE = 1.25
µF
Figure 9. Noise Histogram for Clock Divide by 8 Mode
(CDIV0 = CDIV1 = 1)
04227-0-013
8388592
0 20
40 60 80
CODE
100
8388616
READ NO.
V
DD
= 3V, V
REF
= 2.048V
1.1875Hz UPDATE RATE
T
A
= 25°C, RMS NOISE = 1.25µ
F
Figure 10. Noise Plot in Clock Divide by 8 Mode
(CDIV0 = CDIV1 = 1)
04227-0-015
0
0.5
1.0
1.5
0 0.5 1.0 1.5 2.0 2.5 3.0 3.5 4.0 4.5
RMS NOISE (µV)
5.0
3.0
2.5
2.0
V
REF
(V)
V
DD
= 5V
UPDATE RATE = 16.6Hz
T
A
= 25°C
Figure 11. RMS Noise vs. Reference Voltage