Datasheet

AD7195
Rev. 0 | Page 13 of 44
RMS NOISE AND RESOLUTION
The tables in this section show the rms noise, peak-to-peak
noise, effective resolution, and noise-free (peak-to-peak) resolu-
tion of the AD7195 for various output data rates and gain settings,
with chop disabled and chop enabled for the sinc
4
and sinc
3
filters. The numbers given are for the bipolar input range with
the external 5 V reference. These numbers are typical and are
generated with a differential input voltage of 0 V when the ADC
is continuously converting on a single channel. It is important
to note that the effective resolution is calculated using the rms
noise, whereas the peak-to-peak resolution is calculated based
on peak-to-peak noise. The peak-to-peak resolution represents
the resolution for which there is no code flicker.
SINC
4
CHOP DISABLED
Table 6. RMS Noise (nV) vs. Gain and Output Data Rate
Filter Word
(Decimal)
Output Data
Rate (Hz)
Settling
Time (ms) Gain of 1 Gain of 8 Gain of 16 Gain of 32 Gain of 64 Gain of 128
1023 4.7 852.5 280 96 50 22 10 8.5
640 7.5 533 390 120 54 28 12 10.5
480 10 400 470 130 56 31 14 11.5
96 50 80 1000 150 78 45 33 28
80 60 66.7 1100 170 88 52 36 31
32 150 26.7 1460 220 125 75 55 48
16 300 13.3 1900 285 170 100 75 67
5 960 4.17 3000 480 280 175 140 121
2 2400 1.67 5000 780 440 280 220 198
1 4800 0.83 14,300 1920 1000 550 380 295
Table 7. Peak-to-Peak Noise (nV) vs. Gain and Output Data Rate
Filter Word
(Decimal)
Output Data
Rate (Hz)
Settling
Time (ms) Gain of 1 Gain of 8 Gain of 16 Gain of 32 Gain of 64 Gain of 128
1023 4.7 852.5 1600 500 250 130 65 56
640 7.5 533 2200 650 290 150 80 65
480 10 400 3000 670 300 190 100 70
96 50 80 6000 900 450 280 180 170
80 60 66.7 7200 1100 480 300 220 190
32 150 26.7 8300 1500 750 410 340 310
16 300 13.3 11,000 1700 1000 600 440 430
5 960 4.17 20,000 3000 1800 1100 810 710
2 2400 1.67 32,000 5100 2800 1700 1400 1200
1 4800 0.83 86,000 13,000 6000 3500 2400 1900
Table 8. Effective Resolution (Peak-to-Peak Resolution) vs. Gain and Output Data Rate
Filter Word
(Decimal)
Output Data
Rate (Hz)
Settling
Time (ms)
Gain of 1
1
Gain of 8
1
Gain of 16
1
Gain of 32
1
Gain of 64
1
Gain of 128
1
1023 4.7 852.5 24 (22.6) 23.6 (21.3) 23.6 (21.3) 23.6 (21.2) 23.6 (21.2) 23.1 (20.4)
640 7.5 533 24 (22.1) 23.4 (20.9) 23.4 (20.9) 23.4 (20.9) 23.4 (20.9) 22.8 (20.2)
480 10 400 24 (21.7) 23.3 (20.8) 23.3 (20.8) 23.3 (20.8) 23.3 (20.6) 22.7 (20.1)
96 50 80 23.3 (20.7) 23 (20.4) 22.9 (20.4) 22.7 (20.1) 22.2 (19.7) 21.4 (18.8)
80 60 66.7 23.1 (20.4) 22.8 (20.1) 22.8 (20) 22.5 (20 ) 22.1 (19.4) 21.3 (18.6)
32 150 26.7 22.7 (20.2) 22.4 (19.7) 22.3 (19.7) 22 (19.5) 21.5 (18.8) 20.6 (17.9)
16 300 13.3 22.3 (19.8) 22.1 (19.5) 21.8 (19.3) 21.6 (19) 21 (18.4) 20.1 (17.5)
5 960 4.17 21.7 (18.9) 21.3 (18.7) 21.1 (18.4) 20.8 (18.1) 20.2 (17.6) 19.3 (16.7)
2 2400 1.67 20.9 (18.3) 20.6 (17.9) 20.4 (17.7) 20.1 (17.5) 19.5 (16.8) 18.6 (16)
1 4800 0.83 19.4 (16.8) 19.3 (16.6) 19.3 (16.4) 19.1 (16.4) 18.8 (16) 18 (15.3)
1
The output peak-to-peak (p-p) resolution is listed in parentheses.