5962-8770102RA Datasheet, PDF (8/8 Pages) Analog Devices – CMOS Dual 8-Bit Buffered Multiplying DAC

AD7528
DIGITALLY CONTROLLED DUAL TELEPHONE
ATTENUATOR
In this configuration the AD7528 functions as a 2-channel digi-
tally controlled attenuator. Ideal for stereo audio and telephone
signal level control applications. Table IV gives input codes vs.
attenuation for a 0 dB to 15.5 dB range.
Input
Code
=
256 Ï« 10
exp


−
Attenuation,
20
dB

V_DD
V_IN A
DAC A
A1
V_OUT A
V_OUT B
DB0
DB7
AD7528
DATA BUS
CS
WR
DAC A/DAC B
A2
DAC B
V_IN B
SUGGESTED
OP AMP: AD644
Figure 15. Digitally Controlled Dual Telephone Attenuator
Table IV. Attenuation vs. DAC A, DAC B Code for the Circuit
of Figure 15
Attn. DAC Input
dB Code
0.0 1 1 1 1 1 1 1 1
0.5 1 1 1 1 0 0 1 0
1.0 1 1 1 0 0 1 0 0
1.5 1 1 0 1 0 1 1 1
2.0 1 1 0 0 1 0 1 1
2.5 1 1 0 0 0 0 0 0
3.0 1 0 1 1 0 1 0 1
3.5 1 0 1 0 1 0 1 1
4.0 1 0 1 0 0 0 1 0
4.5 1 0 0 1 1 0 0 0
5.0 1 0 0 1 0 0 0 0
5.5 1 0 0 0 1 0 0 0
6.0 1 0 0 0 0 0 0 0
6.5 0 1 1 1 1 0 0 1
7.0 0 1 1 1 0 0 1 0
7.5 0 1 1 0 1 1 0 0
Code In
Decimal
255
242
228
215
203
192
181
171
162
152
144
136
128
121
114
108
Attn. DAC Input
dB Code
88.0 0 1 1 0 0 1 1 0
88.5 0 1 1 0 0 0 0 0
89.0 0 1 0 1 1 0 1 1
89.5 0 1 0 1 0 1 1 0
10.0 0 1 0 1 0 0 0 1
10.5 0 1 0 0 1 1 0 0
11.0 0 1 0 0 1 0 0 0
11.5 0 1 0 0 0 1 0 0
12.0 0 1 0 0 0 0 0 0
12.5 0 0 1 1 1 1 0 1
13.0 0 0 1 1 1 0 0 1
13.5 0 0 1 1 0 1 1 0
14.0 0 0 1 1 0 0 1 1
14.5 0 0 1 1 0 0 0 0
15.0 0 0 1 0 1 1 1 0
15.5 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
For further applications information the reader is referred to
Analog Devices Application Note on the AD7528.
OUTLINE DIMENSIONS
Dimensions shown in inches and (mm).
20-Lead Cerdip (Q-20)
20-Lead Plastic DIP (N-20)
20
PIN 1
1
11
0.28 (7.11)
0.24 (6.1)
10
0.20 (5.0)
0.14 (3.56)
0.97 (24.64)
0.935 (23.75)
0.14 (3.56)
0.125 (3.17)
0.32 (8.128)
0.29 (7.366)
0.15 (3.8)
0.125 (3.18)
SEATING
PLANE
0.07 (1.78) 0.02 (0.5) 0.11 (2.79)
15؇
0.05 (1.27) 0.016 (0.41) 0.09 (2.28)
0؇
LEAD NO. 1 IDENTIFIED BY DOT OR NOTCH
LEADS ARE SOLDER OR TIN-PLATED KOVAR OR ALLOY 42
0.011 (0.28)
0.009 (0.23)
1.07 (27.18) MAX
20
1
PIN 1
11 _{0.255 (6.477)}
10 ^{0.245 (6.223)}
0.32 (8.128)
0.30 (7.62)
0.145 (3.683)
MIN
0.135 (3.429)
0.125 (3.17)
0.125 (3.175)
MIN
SEATING
0.021 (0.533)
0.015 (0.381)
0.11 (2.79) 0.065 (1.66) ^PLANE
0.09 (2.28) 0.045 (1.15)
0.011 (0.28)
15؇ _{0.009 (0.23)}
0؇
LEAD NO. 1 IDENTIFIED BY DOT OR NOTCH
LEADS ARE SOLDER OR TIN-PLATED KOVAR OR ALLOY 42
20-Lead SOIC (R-20)
0.5118 (13.00)
0.4961 (12.60)
20
11
0.2992 (7.60)
0.2914 (7.40)
0.4193 (10.65)
1
10
0.3937 (10.00)
PIN 1
0.1043 (2.65)
0.0926 (2.35)
0.0291 (0.74)
0.0098 (0.25) ^{؋ 45؇}
0.0118 (0.30)
0.0040 (0.10)
8؇
0.0500
(1.27)
BSC
0.0192 (0.49)
0.0138 (0.35)
SEATING
PLANE
0.0125 (0.32)
0؇
0.0091 (0.23)
0.0500 (1.27)
0.0157 (0.40)
20-Lead Plastic Leaded Chip Carrier (P-20A)
0.048 (1.21)
0.042 (1.07)
00.3.39855((190.7.082))SQ
0.356
0.350
(9.04)
(8.89)
SQ
3
19
4
PIN 1
18
IDENTIFIER
TOP VIEW
(PINS DOWN)
0.02 ⁸
(0.51)
9
MAX
14
13
0.02 (0.51)
MAX
0.180 (4.47)
0.165 (4.19)
0.12 (3.05)
0.09 (2.29)
0.020 (0.51) MIN
0.050
(1.27)
BSC
0.021 (0.53)
0.013 (0.33)
0.032 (0.81)
0.026 (0.66)
0.025 (0.64)
MIN
0.060 (1.53)
MIN
–8–
REV. B