AD7781

Rev. 0 | Page 10 of 16

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.

Parameter

Gain = 128

Gain = 1

Update Rate

10 Hz

16.7 Hz

10 Hz

16.7 Hz

RMS Noise

C Grade

44 nV

65 nV

2.4 μV

2.7 μV

B Grade

55 nV

90 nV

2.4 μV

2.7 μV

P-P Resolution

C Grade

17.6

17.1

18.8

18.7

B Grade

17.3

16.6

18.8

18.7

Parameter

Gain = 128

Gain = 1

Update Rate

10 Hz

16.7 Hz

10 Hz

16.7 Hz

RMS Noise

C Grade

49 nV

69 nV

3.0 μV

2.7 μV

B Grade

60 nV

90 nV

3.0 μV

2.7 μV

P-P Resolution

C Grade

18.2

17.7

19.3

19.4

B Grade

17.9

17.3

19.3

19.4