CAT5114

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Table 1. PIN DESCRIPTIONS

Name

Function

INC

Increment Control

U/D

Up/Down Control

Potentiometer High Terminal

GND

Ground

Wiper Terminal

Potentiometer Low Terminal

CS

Chip Select

Supply Voltage

Pin Function

INC: Increment Control Input

The INC input moves the wiper in the up or down direction

determined by the condition of the U/D input.

U/D: Up/Down Control Input

The U/D input controls the direction of the wiper movement.

When in a high state and CS is low, any high-to-low

transition on INC will cause the wiper to move one

CS is low, any high-to-low transition on INC will cause the

required that this terminal be connected to a potential greater

GND.

the resistor array is controlled by the control inputs, INC,

required that this terminal be connected to a potential less

CS: Chip Select

The chip select input is used to activate the control input of

the CAT5114 and is active low. When in a high state, activity

on the INC and U/D inputs will not affect or change the

position of the wiper.

Device Operation

The CAT5114 operates like a digitally controlled

potentiometer’s wiper. There are 32 available tap positions

terminals. The wiper terminal is connected to one of the 32

taps and controlled by three inputs, INC, U/D and CS. These

inputs control a seven-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 INC

and CS inputs.

With CS set LOW the CAT5114 is selected and will

respond to the U/D and INC inputs. HIGH to LOW

transitions on INC will increment or decrement the wiper

(depending on the state of the U/D input and seven−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 CS transitions HIGH while the INC input

is also HIGH. When the CAT5114 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 INC set low, the CAT5114 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.