CAT5123 ONSEMI [ON Semiconductor], CAT5123 Datasheet - Page 6

• Manufacturer Part Number: CAT5123
• Description: 32-Tap MiniPot Digitally Programmable Potentiometers with 2-Wire Interface
• Manufacturer: ONSEMI [ON Semiconductor]

CAT5110, CAT5118, CAT5119, CAT5123, CAT5124, CAT5125
APPLICATIONS INFORMATION
The MiniPots are intended for circuits requiring
digitally controlled adjustable resistance, such as LCD
contrast control, where voltage biasing adjusts the
display contrast.
Alternative Positive LCD Bias Control
An op amp can be used to provide buffering and gain
on the output of the CAT5110/CAT5125. This can be
done by connecting the wiper output to the positive
input of a noninverting op amp as shown in Figure 3.
Figure 4 shows a similar circuit for the CAT5119/
CAT5124.
Doc. No. MD-2120 Rev. K
Figure 3. Positive LCD Bias Control
Figure 5a. Adjustable Gain Circuit
CAT5110/CAT5125
CAT5118/CAT5123
+5V
L
H
V
IN
W
H
L
V
CC
30V
V
OUT
V
OUT
6
Adjustable Gain
Figure 5 shows how to use either a variable resistor or
a potentiometer to digitally adjust the gain of a
noninverting op amp configuration, by connecting the
Minipot in series with a resistor to ground. The
MiniPots have a low 5ppm/ºC ratiometric tempco that
allows for a very stable adjustable gain configuration
over temperature.
CAT5119/CAT5124
Figure 5b. Adjustable Gain Circuit
Figure 4. Positive LCD Bias Control
L
V
CAT5110/CAT5125
+5V
IN
H
L
W
Characteristics subject to change without notice
H
V
CC
© 2008 SCILLC. All rights reserved.
30V
V
OUT
V
OUT