CAT5259

Doc. No. MD-2000 Rev. H

2

© Catalyst Semiconductor, Inc.

Characteristics subject to change without notice

PIN DESCRIPTIONS

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.

to the terminal connections on a mechanical

potentiometer.

terminal of 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 6 for

more details.

DEVICE OPERATION

The CAT5259 is four resistor arrays integrated with a I²C 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

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 via

the I²C bus. Additional instructions allow data to be 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.

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