1

®

FN8175.2

CAUTION: These devices are sensitive to electrostatic discharge; follow proper IC Handling Procedures.

1-888-INTERSIL or 1-888-468-3774

XDCP is a trademark of Intersil Americas Inc. Copyright Intersil Americas Inc. 2005. All Rights Reserved

All other trademarks mentioned are the property of their respective owners.

X9279

Single Supply/Low Power/256-Tap/2-Wire Bus

Single Digitally-Controlled (XDCP™)

Potentiometer

FEATURES

• 256 Resistor Taps

• 2-Wire Serial Interface for Write, Read, and

Transfer Operations of the Potentiometer

• Wiper Resistance, 100

Ω Typical @ 5V

• 16 Nonvolatile Data Registers for Each

Potentiometer

• Nonvolatile Storage of Multiple Wiper Positions

• Power-on Recall. Loads Saved Wiper Position

on Power-up.

• Standby Current < 5µA Max

•50k

Ω, 100kΩ Versions of End to End Resistance

• Endurance: 100,000 Data Changes per Bit per

Register

• 100 yr. Data Retention

• 14 Ld TSSOP

• Low Power CMOS

• Pb-Free Plus Anneal Available (RoHS Compliant)

DESCRIPTION

The X9279 integrates a single digitally controlled

potentiometer

(XDCP)

on

a

monolithic

CMOS

integrated circuit.

The digital controlled potentiometer is implemented

using 255 resistive elements in a series array.

Between each element are tap points connected to the

wiper terminal through switches. The position of the

wiper on the array is controlled by the user through the

2-Wire

bus

interface.

The

potentiometer

has

associated with it a volatile Wiper Counter Register

(WCR) and a four nonvolatile Data Registers that can

be directly written to and read by the user. The

contents of the WCR controls the position of the wiper

on the resistor array though the switches. Powerup

recalls the contents of the default data register (DR0)

to the WCR.

The

XDCP

can

be

used

as

a

three-terminal

potentiometer or as a two terminal variable resistor in

a wide variety of applications including control,

parameter adjustments, and signal processing.

FUNCTIONAL DIAGRAM

256-taps

50k

Ω and 100kΩ

POT

2-Wire

Bus

wiper

Interface

Power-on Recall

Wiper Counter

Register (WCR)

Data Registers

16 Bytes

Bus

Interface

and Control

Address

Data

Status

Write

Read

Transfer

Inc/Dec

Control

Data Sheet

September 27, 2005