ad7531jd National Semiconductor Corporation, ad7531jd Datasheet - Page 7

• Manufacturer Part Number: ad7531jd
• Description: 10-bit, 12-bit Binary Multiplying D/a Converter
• Manufacturer: National Semiconductor Corporation

Typical Applications
FIGURE 10 Analog-to-Digital Divider (or Digitally Gain Controlled Amplifier)
V
where V


OUT
By connecting the DAC in the feedback loop of an opera-
tional amplifier a linear digitally control gain block can be
realized
Note that with all digital inputs low the gain of the amplifier
is infinity that is the op amp will saturate In other words we
cannot divide the V
V
OUT
(Continued)
e
FIGURE 11 Digitally controlled Amplifier-Attenuator
e

A1
REF
V
2
REF
a
A2
can be an AC signal
%
4
A1
A1
2
2
a
b
a
a
V
A3
8
REF
A2
A2
4
4
a
REF
a
a
1024
by zero
A10
a
a
1024
1024
J
A10
A10
7
–
where 0
N
N
N
or V
e
e
e
OUT
0 for A
1 for A10
1023 for A
e
s
V
N
N
REF
s
e
e
N
1023
all zeros

e
1 A1–A9
1023
all 1’s
N
b
N
e
J
0
TL H 5689 – 7
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