FN8195 Rev.1.00

Page 1 of 19

April 26, 2006

FN8195

Rev.1.00

April 26, 2006

X9420

Low Noise/Low Power/SPI Bus Single Digitally Controlled (XDCP™)

Potentiometer

DATASHEET

FEATURES

• Solid-State Potentiometer

• SPI Serial Interface

• Register Oriented Format

—Direct read/write/transfer wiper positions

—Store as many as four positions per

potentiometer

• Power Supplies

—V+ = 2.7V to 5.5V

—V– = -2.7V to -5.5V

• Low Power CMOS

—Standby current < 1µA

• High Reliability

—Endurance–100,000 data changes per bit per

register

—Register data retention–100 years

• 8-bytes of Nonvolatile EEPROM Memory

•10k

 or 2.5k Resistor Arrays

• Resolution: 64 Taps Each Pot

• 14 Ld TSSOP and 16 Ld SOIC Packages

• Pb-Free Plus Anneal Available (RoHS Compliant)

DESCRIPTION

The X9420 integrates a single digitally controlled

potentiometers (XDCP) on a monolithic CMOS

integrated microcircuit.

The digitally controlled potentiometer is implemented

using 63 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 SPI bus

interface. The potentiometer has associated with it a

volatile Wiper Counter Register (WCR) and 4

nonvolatile Data Registers (DR0:DR3) 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 through the switches. Power-up recalls

the contents of 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.

BLOCK DIAGRAM

R0 R1

R2 R3

Wiper

Counter

Register

(WCR)

Interface

and

Control

Circuitry

HOLD

CS

SI

A0

Data

8

SCK

S0

NOT RECOMMENDED FOR NEW DESIGNS

POSSIBLE SUBSTITUTE PRODUCT

ISL22416, ISL22419, ISL95311, ISL95711