AD7781 Analog Devices, AD7781 Datasheet - Page 10

• Manufacturer Part Number: AD7781
• Description: 20-Bit, Pin-Programmable, Ultralow Power Sigma-Delta ADC
• Manufacturer: Analog Devices

Specifications of AD7781

• Resolution (bits): 20bit
• # Chan: 1
• Sample Rate: 16.7SPS
• Interface: Ser,SPI
• Analog Input Type: Diff-Bip
• Ain Range: ± (Vref/Gain) ,10V p-p,78 mV p-p
• Adc Architecture: Sigma-Delta
• Pkg Type: SOIC,SOP

AD7781
OUTPUT NOISE AND RESOLUTION
Table 7 and Table 8 show the rms noise of the AD7781 for the two output data rates and gain settings when using a 3 V and a 5 V reference.
These numbers are typical and are generated with a differential input voltage of 0 V. The peak-to-peak (p-p) resolution is also listed. The
p-p resolution represents the resolution for which there is no code flicker. These numbers are typical.
Table 7. RMS Noise and Peak-to-Peak Resolution When AV
Parameter
Update Rate
RMS Noise
P-P Resolution
Table 8. RMS Noise and Peak-to-Peak Resolution When AV
Parameter
Update Rate
RMS Noise
P-P Resolution
C Grade
B Grade
C Grade
B Grade
C Grade
B Grade
C Grade
B Grade
10 Hz
44 nV
55 nV
17.6
17.3
10 Hz
49 nV
60 nV
18.2
17.9
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Gain = 128
Gain = 128
DD
DD
= 3 V and V
= 5 V and V
16.7 Hz
65 nV
90 nV
17.1
16.6
16.7 Hz
69 nV
90 nV
17.7
17.3
REF
REF
= 3 V
= 5 V
10 Hz
2.4 μV
2.4 μV
18.8
18.8
10 Hz
3.0 μV
3.0 μV
19.3
19.3
Gain = 1
Gain = 1
16.7 Hz
2.7 μV
2.7 μV
18.7
18.7
16.7 Hz
2.7 μV
2.7 μV
19.4
19.4