CAT5120, CAT5121, CAT5122
16-Tap MiniPot™ Digitally Programmable
Potentiometers with 2-Wire Interface
FEATURES
0.3µA Ultra-low standby current
Single-supply operation: 2.7V to 5.5V
Glitchless switching between resistor taps
Power-on reset to midscale
2-wire up/down serial interface
Resistance values: 10kΩ, 50kΩ and 100kΩ
Available in SC-70 and SOT-23 packages
DESCRIPTION
CAT5120/5121/5122 linear-taper digitally programmable
potentiometers perform the same function as a
mechanical potentiometer or a variable resistor. These
devices consist of a fixed resistor and a wiper contact
with 16-tap points that are digitally controlled through a
2-wire up/down serial interface.
The CAT5120 is configured as a potentiometer. The
CAT5121 and CAT5122 are configured as variable
resistors. See
Pin Configurations
for part functionality.
Three resistance values are available: 10kΩ, 50kΩ and
100kΩ. These are available in space-saving 5-pin and
6-pin SC-70 and SOT-23 packages.
APPLICATIONS
LCD screen adjustment
Volume control
Mechanical potentiometer replacement
Gain adjustment
Line impedance matching
FUNCTIONAL DIAGRAM
H
V
DD
GND
16-POSITION
DECODER
CS
UP-DOWN
COUNTER
W
U/D
PIN CONFIGURATION
SC-70
SOT-23
V
DD
1
6
H
V
DD
1
SC-70
SOT-23
5
H
L
PIN DESCRIPTIONS
Name
V
DD
GND
4
CS
Description
Power Supply
Ground
¯¯¯¯¯
¯¯
Up/Down Control Input. With CS low, a
low-to-high transition increments or
decrements the wiper position.
¯¯
Chip Select Input. A high-to-low CS
transition determines the mode:
¯
increment if U/D is high, or decrement if
¯
U/D is low.
Low Terminal of Resistor
Wiper Terminal of Resistor
High Terminal of Resistor
GND 2
5 W
GND 2
CAT5120
U/D 3
4
CS
U/D 3
CAT5122
¯
U/D
SC-70
SOT-23
V
DD
1
6
H
¯¯
CS
L
W
H
GND 2
5 L
CAT5121
U/D 3
4
CS
© Catalyst Semiconductor, Inc.
Characteristics subject to change without notice
1
Doc. No. MD-2121 Rev. E
CATALYST [ CATALYST SEMICONDUCTOR ]
