2

CAT5259

Document No. 2000, Rev. F

PIN DESCRIPTION

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 communica-

tion with the CAT5259.

to the terminal connections on a mechanical

potentiometer.

Wiper

terminal of a mechanical potentiometer.

WP

WP

WP

WP

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 2-wire 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

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 2-wire 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.

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