AD7791 Analog Devices, AD7791 Datasheet - Page 9

• Manufacturer Part Number: AD7791
• Description: 24-Bit, Single-Channel, Ultra Low Power, Sigma Delta A/D Converter
• Manufacturer: Analog Devices

Specifications of AD7791

• Resolution (bits): 24bit
• # Chan: 1
• Sample Rate: n/a
• Interface: Ser,SPI
• Analog Input Type: Diff-Uni
• Ain Range: (2Vref) p-p
• Adc Architecture: Sigma-Delta
• Pkg Type: SOP

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