Preliminary Technical Data

AD7190

Rev.PrD 7/08 | Page 13

CHOP ENABLED

Table 11 shows the AD7190’s rms noise for some of the update

rates and gain settings. The numbers given are for the bipolar

input range with an external 5 V reference. These numbers are

typical and are generated with a differential input voltage of 0 V.

Table 12 shows the effective resolution, while the output peak-

to-peak (p-p) resolution is listed in brackets. 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 will be no code flicker. These numbers are typical

and are rounded to the nearest half-LSB.

Table 11. RMS Noise (nV) vs. Gain and Output Update Rate (continuous conversion mode) Using a 5 V Reference - Chop Enabled

Filter Word

(Decimal)

Update

Rate (Hz)

Gain of 1

Gain of 8

Gain of 16

Gain of 32

Gain of 64

Gain of 128

1023

1.56

125

18.74

9.35

7.44

6.15

5.43

640

2.5

173

21.92

11.4

9.28

7.76

7.09

480

3.33

195

29

14.48

10.90

9.06

7.59

96

16.6

429

66

34

26.11

20.99

18.14

16

100

990

145

79.2

59.4

51.77

44.62

2

800

40666

4950

2524

1252

634

328

1

1600

309783

38672

19332

10055

4872

2461

Table 12. Typical Resolution (Bits) vs. Gain and Output Update Rate (continuous conversion mode) Using a 5 V Reference - Chop

Enabled

Filter Word

(Decimal)

Update

Rate (Hz)

Gain of 1

Gain of 8

Gain of 16

Gain of 32

Gain of 64

Gain of 128

1023

1.56

24 (23.5)

24 (23.5)

24 (23.5)

24 (22.5)

24 (22)

24 (21.5)

640

2.5

24 (23.5)

24 (23)

24 (23)

24 (22.5)

24 (21.5)

23.5 (21)

480

3.33

24 (23)

24 (22.5)

24 (22.5)

24 (22)

24 (21.5)

23 (20.5)

96

16.6

24 (22)

24 (21.5)

24 (21.5)

23.5 (21)

23 (20.5)

22 (19.5)

16

100

23.5 (21)

23 (20.5)

23 (20.5)

22.5 (20)

21.5 (19)

21 (18.5)

2

800

18 (15.5)

18 (15.5)

18 (15.5)

18 (15.5)

18 (15.5)

18 (15.5)

1

1600

15 (12.5)

15 (12.5)

15 (12.5)

15 (12.5)

15 (12.5)

15 (12.5)