Data Sheet
By establishing a reference at the low side of a current setting
resistor, an output current may be defined as a function of input
voltage, gain, and the value of that resistor. Because only a small
current is demanded at the input of the buffer amplifier (A2)
AD524
the forced current, IL, largely flows through the load. Offset and
drift specifications of A2 must be added to the output offset and
drift specifications of the AD524.
–IN
+IN
–VS
+VS
1µF
35V
ANALOG
COMMON
1 PROTECTION
2 PROTECTION
3
INPUT
OFFSET
TRIM R1
4
10kΩ
5
6
+VS
20kΩ
20kΩ 20kΩ
20kΩ
20kΩ
16
15
R2
10kΩ
14
OUTPUT
OFFSET
TRIM
G = 10
K1
NC
4.44kΩ
13
404Ω
12
RELAY
SHIELDS
40Ω
11
G = 100
K2
G = 1000
K3
7
A1
AD524
8
20kΩ
10
OUT
9
+5V
K1
D1 K2
D2 K3
D3
C1 C2
K1 – K3 =
THERMOSEN DM2C
4.5V COIL
D1 – D3 = IN4148
GAIN TABLE
A B GAIN
0 0 10
0 1 1000
1 0 100
1 11
INPUTS
GAIN
A
RANGE B
+5V
1
16
Y0
2
15
Y1
3
4
74LS138 14
DECODER 13
Y2
5
6
7
NC = NO CONNECT
Figure 47. Three-Decade Gain Programmable Amplifier
1
16
2
3 7407N
4
BUFFER
DRIVER
5
6
7
10µF
LOGIC
COMMON
Rev. G | Page 19 of 25