Datasheet

AD7796/AD7797
Rev. A | Page 9 of 24
RMS NOISE AND RESOLUTION SPECIFICATIONS
Tabl e 6 shows the rms noise of the AD7796/AD7797 for some
of the update rates. The numbers given are for the bipolar input
range with an external 2.5 V reference. These numbers are
typical and are generated with a differential input voltage of 0 V.
Tabl e 7 and Table 8 show the effective resolution, while the
output peak-to-peak (p-p) resolution is shown in brackets. It is
important to note that the effective resolution is calculated
using the rms noise, while the p-p resolution is based on the 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 0.5 LSB.
Table 6. RMS Noise (μV) vs. Output Update Rate for the
AD7796/AD7797 Using a 2.5 V Reference
Update Rate (Hz) RMS Noise (μV)
4.17
0.065
6.25
0.07
8.33
0.08
10
0.09
12.5
0.1
16.7
0.12
33.2
0.17
50
0.21
62
0.23
123
0.43
Table 7. Typical Resolution (Bits) vs. Output Update Rate for
the AD7797 Using a 2.5 V Reference
Update Rate (Hz) Effective Bits (p-p)
4.17
19 (16.5)
6.25
19 (16.5)
8.33
19 (16)
10
18.5 (16)
12.5
18.5 (16)
16.7
18.5 (15.5)
33.2
18 (15)
50
17.5 (15)
62
17.5 (14.5)
123
16.5 (13.5)
Table 8. Typical Resolution (Bits) vs. Output Update Rate for
the AD7796 Using a 2.5 V Reference
Update Rate (Hz) Effective Bits (p-p)
4.17
16 (16)
6.25
16 (16)
8.33
16 (16)
10
16 (16)
12.5
16 (16)
16.7
16 (15.5)
33.2
16 (15)
50
16 (15)
62
16 (14.5)
123
16 (13.5)