CAT5133ZI-10-GT3 Datasheet, PDF (2/10 Pages) ON Semiconductor – 16 Volt Digitally Programmable Potentiometer with 128 Taps and an Increment Decrement Interface

CAT5133
PIN CONFIGURATION
MSOP Package (GZ)
PIN DESCRIPTIONS
Pin Name Function
1
U/D¯
Up/Down Data Input – Determines the direction of
movement of the wiper
2 GND Ground
3
V_CC Logic Supply Voltage (2.7V to 5.5V)
4
¯C¯S¯ Chip Select – The chip is selected when the input is low.
5 N/C No Connect
6
R_H High Reference Terminal for the Potentiometer
7
R_W Wiper Terminal for the Potentiometer
8
R_L Low Reference Terminal for the Potentiometer
9
V₊ Analog Bias Voltage Input (+8.0V to +16.0V)
10
I¯N¯C¯
Increment Input – Moves the wiper in the direction
determined by the Up/Down input on each negative edge
DEVICE OPERATION
The CAT5133 operates like a digitally controlled
potentiometer with R_H and R_L equivalent to the high
and low terminals and R_W equivalent to the mechanical
potentiometer’s wiper. There are 128 available tap
positions including the resistor end points, R_H and R_L.
There are 127 resistor elements connected in series
between the R_H and R_L terminals. The wiper terminal is
connected to one of the 128 taps and controlled by
three inputs, I¯N¯C¯, U/D¯ and ¯C¯S¯. These inputs control a
7-bit up/down counter whose output is decoded to
select the wiper position. The selected wiper position
can be stored in nonvolatile memory using the I¯N¯C¯ and
¯C¯S¯ inputs.
With ¯C¯S¯ set LOW the CAT5133 is selected and will
respond to the U/D¯ and I¯N¯C¯ inputs. HIGH to LOW
transitions on I¯N¯C¯ will increment or decrement the
wiper (depending on the state of the U/D¯ input and
7-bit counter). The wiper, when at either fixed terminal,
acts like its mechanical equivalent and does not move
beyond the last position. The value of the counter is
stored in nonvolatile memory whenever ¯C¯S¯ transitions
HIGH while the I¯N¯C¯ input is also HIGH. When the
CAT5133 is powered-down; the last stored wiper
counter position is maintained in the nonvolatile
memory. When power is restored, the contents of the
memory are recalled and the counter is set to the
value stored.
With I¯N¯C¯ set low, the CAT5133 may be de-selected
and powered down without storing the current wiper
position in nonvolatile memory. This allows the system
to always power up to a preset value stored in
nonvolatile memory.
OPERATION MODES
I¯N¯C¯
¯C¯S¯
High to Low
Low
High to Low
Low
High
Low to High
Low
Low to High
X
High
U/D¯
High
Low
X
X
X
Operation
Wiper toward H
Wiper toward L
Store Wiper Position
No Store, Return to Standby
Standby
Doc. No. MD-2125 Rev. D
2
© 2008 SCILLC. All rights reserved.
Characteristics subject to change without notice