CAT5259

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3

PIN DESCRIPTIONS

Table 1. PIN DESCRIPTIONS

Pin #

Name

Function

1

NC

No Connect

2

A0

Device Address, LSB

3

Wiper Terminal for Potentiometer 3

4

High Reference Terminal for

Potentiometer 3

5

Low Reference Terminal for Potentiometer 3

6

NC

No Connect

7

Supply Voltage

8

Low Reference Terminal for Potentiometer 0

9

High Reference Terminal for

Potentiometer 0

10

Wiper Terminal for Potentiometer 0

11

A2

Device Address

12

WP

Write Protection

13

SDA

Serial Data Input/Output

14

A1

Device Address

15

Low Reference Terminal for Potentiometer 1

16

High Reference Terminal for

Potentiometer 1

17

Wiper Terminal for Potentiometer 1

18

GND

Ground

19

NC

No Connect

20

Wiper Terminal for Potentiometer 2

21

High Reference Terminal for

Potentiometer 2

22

Low Reference Terminal for Potentiometer 2

23

SCL

Bus Serial Clock

24

A3

Device Address

SCL: Serial Clock

The CAT5259 serial clock input pin is used to clock all

data transfers into or out of the device.

SDA: Serial Data

The CAT5259 bidirectional serial data pin is used to

transfer data into and out of the device. The SDA pin is an

open drain output and can be wire-Ored with the other open

drain or open collector I/Os.

A0, A1, A2, A3: Device Address Inputs

These inputs set the device address when addressing

multiple devices. A total of sixteen devices can be addressed

on a single bus. A match in the slave address must be made

with the address input in order to initiate communication

with the CAT5259.

terminal connections on a mechanical potentiometer.

a mechanical potentiometer.

WP: Write Protect Input

The WP pin when tied low prevents non-volatile writes to

the device (change of wiper control register is allowed) and

when tied high or left floating normal read/write operations

are allowed. See Write Protection on page 7 for more details.

DEVICE OPERATION

serial interface logic, four 8-bit wiper control registers and

sixteen 8-bit, non-volatile memory data registers. Each

resistor array contains 255 separate resistive elements

connected in series. The physical ends of each array are

equivalent to the fixed terminals of a mechanical

at the ends of the series resistors are connected to the output

one tap point for each potentiometer is connected to its wiper

terminal at a time and is determined by the value of the wiper

control register. Data can be read or written to the wiper

control registers or the non-volatile memory data registers

transferred between the wiper control registers and each

respective potentiometer’s non-volatile data registers. Also,

the device can be instructed to operate in an “increment/

decrement” mode.