Datasheet

8
FN8222.3
July 20, 2009
Basic Configurations of Electronic Potentiometers
Basic Circuits
V
R
V
R
I
THREE TERMINAL POTENTIOMETER;
VARIABLE VOLTAGE DIVIDER
TWO TERMINAL VARIABLE RESISTOR;
VARIABLE CURRENT
V
H
/R
H
V
L
/R
L
V
W
/R
W
CASCADING TECHNIQUESBUFFERED REFERENCE VOLTAGE
–
+
+5V
R
1
+V
-5V
V
W
V
REF
V
OUT
OP-07
V
W
/R
W
V
W
/R
W
+V
+V +V
X
(a) (b)
V
OUT
= V
W
/R
W
NONINVERTING AMPLIFIER
V
O
= (1+R
2
/R
1
)V
S
VOLTAGE REGULATOR
R
1
R
2
I
adj
V
O
(REG) = 1.25V (1+R
2
/R
1
)+I
adj
R
2
V
O
(REG)V
IN
317
OFFSET VOLTAGE ADJUSTMENT
+
–
V
S
V
O
R
2
R
1
100kΩ
10kΩ10kΩ
10kΩ
-12V+12V
TL072
COMPARATOR WITH HYSTERESIS
V
UL
= {R
1
/(R
1
+ R
2
)} V
O
(MAX)
V
LL
= {R
1
/(R
1
+ R
2
)} V
O
(MIN)
+
–
V
S
V
O
R
2
R
1
LM308A
+5V
-5V
+
–
V
S
V
O
R
2
R
1
} }
LT311A
(FOR ADDITIONAL CIRCUITS SEE AN1145)
X9C102, X9C103, X9C104, X9C503