Preliminary Technical Data

AD7190

Rev.PrD 7/08 | Page 11

CHOP ENABLED

Table 7 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 8 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 7. 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

1.175

123

17.47

8.94

7.07

5.87

5

640

1.875

138

21.41

10.27

8.68

7.33

7.07

480

2.5

174

26.87

13.67

10

8.49

7.25

96

12.5

395

61.52

31.11

25.22

19.64

17.9

16

75

950

132

74.25

51.5

48.49

37.24

2

600

3008

412

228

164

141

118

1

1200

9192

1255

636

479

351

266

Table 8. 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

1.175

24 (23.5)

24 (23.5)

24 (23.5)

24 (22.5)

24 (22)

24 (21.5)

640

1.875

24 (23.5)

24 (23)

24 (23)

24 (22.5)

24 (21.5)

23.5 (21)

480

2.5

24 (23)

24 (22.5)

24 (22.5)

24 (22)

24 (21.5)

23 (20.5)

96

12.5

24 (22)

24 (21.5)

24 (21.5)

23.5 (21)

23 (20.5)

22 (19.5)

16

75

23.5 (21)

23 (20.5)

23 (20.5)

22.5 (20)

21.5 (19)

21 (18.5)

2

600

21.5 (19)

21.5 (19)

21.5 (19)

21 (18.5)

20 (17.5)

19.5 (17)

1

1200

20 (17.5)

20 (17.5)

20 (17.5)

19.5 (17)

18.5 (16)

18 (15.5)