AD7628TQ AD [Analog Devices], AD7628TQ Datasheet - Page 8

• Manufacturer Part Number: AD7628TQ
• Description: CMOS Dual 8-Bit Buffered Multiplying DAC
• Manufacturer: AD [Analog Devices]

AD7628
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
Attn. dB Code
0.0
0.5
1.0
1.5
2.0
2.5
3.0
3.5
4.0
4.5
5.0
5.5
6.0
6.5
7.0
7.5
Figure 15. Digitally Controlled Dual Telephone Attenuator
Table IV. Attenuation vs. DAC A, DAC B Code for the
Circuit of Figure 15
DAC Input
1 1 1 1 1 1 1 1
1 1 1 1 0 0 1 0
1 1 1 0 0 1 0 0
1 1 0 1 0 1 1 1
1 1 0 0 1 0 1 1
1 1 0 0 0 0 0 0
1 0 1 1 0 1 0 1
1 0 1 0 1 0 1 1
1 0 1 0 0 0 1 0
1 0 0 1 1 0 0 0
1 0 0 1 0 0 0 0
1 0 0 0 1 0 0 0
1 0 0 0 0 0 0 0
0 1 1 1 0 0 1
0 1 1 1 0 0 1 0
0 1 1 0 1 1 0 0
Code in
Decimal Attn. dB Code
255
242
228
215
203
192
181
171
162
152
144
136
128
121
114
108
Attenuation, dB
10.0
10.5
11.0
11.5
12.0
12.5
13.0
13.5
14.0
14.5
15.0
15.5
8.0
8.5
9.0
9.5
20
DAC Input
0 1 1 0 0 1 1 0
0 1 1 0 0 0 0 0
0 1 0 1 1 0 1 1
0 1 0 1 0 1 1 0
0 1 0 1 0 0 0 1
0 1 0 0 1 1 0 0
0 1 0 0 1 0 0 0
0 1 0 0 0 1 0 0
0 1 0 0 0 0 0 0
0 0 1 1 1 1 0 1
0 0 1 1 1 0 0 1
0 0 1 1 0 1 1 0
0 0 1 1 0 0 1
0 0 1 1 0 0 0 0
0 0 1 0 1 1 1 0
0 0 1 0 1 0 1 1
Code in
Decimal
102
96
91
86
81
76
72
68
64
61
57
54
51
48
46
43
–8–
MECHANICAL INFORMATION
Dimensions shown in inches and (mm).
20-Pin Plastic DIP (N Suffix)
OUTLINE DIMENSIONS
20-Pin Cerdip (Q Suffix)
Chip Carrier (P Suffix)
Carrier (E Suffix)
Plastic Leaded
Leadless Chip
20-Terminal
20-Terminal
REV. A