AD7795 Analog Devices, AD7795 Datasheet - Page 14

• Manufacturer Part Number: AD7795
• Description: 6-Channel, Low Noise, Low Power, 16-Bit Sigma Delta ADC with On-Chip In-Amp and Reference
• Manufacturer: Analog Devices

Specifications of AD7795

• Resolution (bits): 16bit
• # Chan: 6
• 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

AD7794/AD7795
Internal Reference
Table 8 shows the AD7794/AD7795 rms noise 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
while the output peak-to-peak (p-p) resolution is listed in brackets.
Table 8. RMS Noise (μV) vs. Gain and Output Update Rate Using an Internal 1.17 V Reference with Chop Enabled
Update Rate (Hz)
4.17
8.33
16.7
33.2
62
123
242
470
Table 9.
Effective Resolution (Bits) vs. Gain and Output Update Rate for the AD7794 Using an Internal 1.17 V Reference with Chop Enabled
Update Rate (Hz)
4.17
8.33
16.7
33.2
62
123
242
470
Table 10.
Effective Resolution (Bits) vs. Gain and Output Update Rate for the AD7795 Using an Internal 1.17 V Reference with Chop Enabled
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. D | Page 14 of 36
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)
It is important to note that the effective resolution is calculated
using the rms noise while the p-p resolution is calculated based
on peak-to-peak noise. The p-p resolution represents the
resolution for which there is no code flicker. These numbers are
typical and 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
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 (16)
16 (15.5)
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)
16 (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)
16 (13.5)
15.5 (13)
15 (12.5)