Datasheet

AD7628
–8–
REV. A
MECHANICAL INFORMATION
OUTLINE DIMENSIONS
Dimensions shown in inches and (mm).
C1029a–8–3/88
PRINTED IN U.S.A.
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 × 10 exp
−
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
0.0 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)