AD7628

–8–

REV. A

MECHANICAL INFORMATION

OUTLINE DIMENSIONS

Dimensions shown in inches and (mm).

DIGITALLY CONTROLLED DUAL

TELEPHONE ATTENUATOR

In this configuration, the AD7628 functions as a 2-channel

digitally controlled attenuator; ideal for stereo audio and tele-

phone signal level control applications. Table IV gives input

codes vs. attenuation for a 0 dB to 15.5 dB range.

Input Code = 256

Attenuation, dB

20









Figure 15. Digitally Controlled Dual Telephone Attenuator

Table IV. Attenuation vs. DAC A, DAC B Code for the

Circuit of Figure 15

DAC Input

Code in

DAC Input

Code in

Attn. dB Code

Decimal Attn. dB

Code

Decimal

1 1 1 1 1 1 1 1

255

8.0

0 1 1 0 0 1 1 0

102

0.5

1 1 1 1 0 0 1 0

242

8.5

0 1 1 0 0 0 0 0

96

1.0

1 1 1 0 0 1 0 0

228

9.0

0 1 0 1 1 0 1 1

91

1.5

1 1 0 1 0 1 1 1

215

9.5

0 1 0 1 0 1 1 0

86

2.0

1 1 0 0 1 0 1 1

203

10.0

0 1 0 1 0 0 0 1

81

2.5

1 1 0 0 0 0 0 0

192

10.5

0 1 0 0 1 1 0 0

76

3.0

1 0 1 1 0 1 0 1

181

11.0

0 1 0 0 1 0 0 0

72

3.5

1 0 1 0 1 0 1 1

171

11.5

0 1 0 0 0 1 0 0

68

4.0

1 0 1 0 0 0 1 0

162

12.0

0 1 0 0 0 0 0 0

64

4.5

1 0 0 1 1 0 0 0

152

12.5

0 0 1 1 1 1 0 1

61

5.0

1 0 0 1 0 0 0 0

144

13.0

0 0 1 1 1 0 0 1

57

5.5

1 0 0 0 1 0 0 0

136

13.5

0 0 1 1 0 1 1 0

54

6.0

1 0 0 0 0 0 0 0

128

14.0

0 0 1 1 0 0 1

51

6.5

0 1 1 1 0 0 1

121

14.5

0 0 1 1 0 0 0 0

48

7.0

0 1 1 1 0 0 1 0

114

15.0

0 0 1 0 1 1 1 0

46

7.5

0 1 1 0 1 1 0 0

108

15.5

0 0 1 0 1 0 1 1

43

20-Pin Cerdip (Q Suffix)

20-Pin Plastic DIP (N Suffix)

20-Terminal

Leadless Chip

Carrier (E Suffix)

20-Terminal

Plastic Leaded

Chip Carrier (P Suffix)