Datasheet

AD538
Rev. E | Page 14 of 16
00959-018
25kΩ
25kΩ
100Ω
25kΩ
25kΩ
ANTILOG
LOG
OUTPUT
100Ω
R
B
100Ω
*
R
C
100Ω
*
RATIO MATCH 1% METAL FILM
RESISTORS FOR BEST ACCURACY
*
AD538
I
Y
A
D
I
X
V
X
C
D1
IN4148
V
Y
811
17
16
15
14
13
12
11
10
2
3
4
5
6
7
8
9
LOG
RATIO
INTERNAL
VOLTAGE
REFERENCE
SIGNAL
GND
PWR
GND
I
Z
V
Z
V
O
I
+15V
–15V
B
+10V
+2V+2V
1kΩ
100Ω
SCALE FACTOR
TRIM
1kΩ
V
IN
20kΩ
20kΩ
10kΩ
5kΩ
OPTIONAL
ABSOLUTE VALUE SECTION
20kΩ
+V
S
V
OS
IN4148
AD OP-07
OR AD811
(V
OS
TAP
TO –V
S
)
IN4148
–V
S
2
7
1
8
6
4
3
V
IN
1V
V
O
= 1V
V
O
Figure 17. Square Root Circuit