AD7793 Analog Devices, AD7793 Datasheet - Page 12

• Manufacturer Part Number: AD7793
• Description: 3-Channel, Low Noise, Low Power, 24-Bit Sigma Delta ADC with On-Chip In-Amp and Reference
• Manufacturer: Analog Devices

Specifications of AD7793

• Resolution (bits): 24bit
• # Chan: 3
• Sample Rate: n/a
• Interface: Ser,SPI
• Analog Input Type: Diff-Uni
• Ain Range: (2Vref/PGA Gain) p-p
• Adc Architecture: Sigma-Delta
• Pkg Type: SOP

AD7792/AD7793
INTERNAL REFERENCE
Table 8 shows the output rms noise of the AD7792/AD7793 for
some of the update rates and gain settings. The numbers given
are for the bipolar input range with the internal 1.17 V
reference. These numbers are typical and are generated with a
differential input voltage of 0 V. Table 9 and Table 10 show the
effective resolution, with the output peak-to-peak (p-p)
Table 8. Output RMS Noise (μV) vs. Gain and Output Update Rate for the AD7792 and AD7793 Using the Internal Reference
Update Rate (Hz)
4.17
8.33
16.7
33.2
62
123
242
470
Table 9. Typical Resolution (Bits) vs. Gain and Output Update Rate for the AD7793 Using the Internal Reference
Update Rate (Hz)
4.17
8.33
16.7
33.2
62
123
242
470
Table 10. Typical Resolution (Bits) vs. Gain and Output Update Rate for the AD7792 Using the Internal Reference
Update Rate (Hz)
4.17
8.33
16.7
33.2
62
123
242
470
Gain of 1
0.81
1.18
1.96
2.99
3.6
5.83
11.22
12.46
Gain of 1
21.5 (19)
21 (18.5)
20 (17.5)
19.5 (17)
19.5 (17)
18.5 (16)
17.5 (15)
17.5 (15)
Gain of 1
16 (16)
16 (16)
16 (16)
16 (16)
16 (16)
16 (16)
16 (15)
16 (15)
Gain of 2
0.67
1.11
1.72
2.48
3.25
5.01
8.64
10.58
Gain of 2
20.5 (18)
20 (17.5)
19.5 (17)
19 (16.5)
18.5 (16)
18 (15.5)
17 (14.5)
17 (14.5)
Gain of 2
16 (16)
16 (16)
16 (16)
16 (16)
16 (16)
16 (15.5)
16 (14.5)
16 (14.5)
Gain of 4
0.32
0.41
0.55
0.83
1.03
1.69
2.69
4.58
Gain of 4
21 (18.5)
20.5 (18)
20 (17.5)
19.5 (17)
19 (16.5)
18.5 (16)
17.5 (15)
17 (14.5)
Gain of 4
16 (16)
16 (16)
16 (16)
16 (16)
16 (16)
16 (16)
16 (15)
16 (14.5)
Rev. B | Page 12 of 32
Gain of 8
0.2
0.25
0.36
0.48
0.65
0.96
1.9
2
Gain of 8
20.5 (18)
20 (17.5)
19.5 (17)
19 (16.5)
19 (16.5)
18 (15.5)
17 (14.5)
17 (14.5)
Gain of 8
16 (16)
16 (16)
16 (16)
16 (16)
16 (16)
16 (15.5)
16 (14.5)
16 (14.5)
resolution given in parentheses for the AD7793 and AD7792,
respectively. It is important to note that the effective resolution
is calculated using the rms noise, while the p-p resolution is
calculated based on p-p noise. The p-p resolution represents the
resolution for which there is no code flicker. These numbers are
typical and are rounded to the nearest LSB.
Gain of 16
0.13
0.16
0.25
0.33
0.46
0.67
1.04
1.27
Gain of 16
20 (17.5)
20 (17.5)
19 (16.5)
19 (16.5)
18.5 (16)
17.5 (15)
17 (14.5)
17 (14.5)
Gain of 16
16 (16)
16 (16)
16 (16)
16 (16)
16 (16)
16 (15)
16 (14.5)
16 (14.5)
Gain of 32
Gain of 32
Gain of 32
16 (16)
16 (15.5)
0.065
0.078
0.11
0.17
0.2
0.32
0.45
0.63
20 (17.5)
20 (17.5)
19.5 (17)
18.5 (16)
18.5 (16)
18 (15.5)
17.5 (15)
17 (14.5)
16 (16)
16 (16)
16 (16)
16 (16)
16 (15)
16 (14.5)
Gain of 64
0.04
0.058
0.088
0.13
0.15
0.25
0.35
0.50
Gain of 64
20 (17.5)
19 (16.5)
18.5 (16)
18 (15.5)
18 (15.5)
17 (14.5)
16.5 (14)
16 (13.5)
Gain of 64
16 (16)
16 (16)
16 (16)
16 (15.5)
16 (15.5)
16 (14.5)
16 (14)
15.5 (13.5)
Gain of 128
0.039
0.059
0.088
0.12
0.15
0.26
0.34
0.49
Gain of 128
19 (16.5)
18 (15.5)
17.5 (15)
17 (14.5)
17 (14.5)
16 (13.5)
15.5 (13)
15 (12.5)
Gain of 128
16 (16)
16 (15.5)
16 (15)
16 (14.5)
16 (14.5)
15.5 (13.5)
15 (13)
14.5 (12.5)