1

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X9221A

64 Taps, 2-Wire Serial Bus

Dual Digitally Controlled Potentiometer

(XDCP™)

FEATURES

• Two XDCPs in one package

• 2-wire serial interface

• Register oriented format, 8 registers total

—Directly write wiper position

—Read wiper position

—Store as many as four positions per pot

• Instruction format

—Quick transfer of register contents to resistor

array

• Direct write cell

—Endurance–100,000 writes per bit per register

• Resistor array values

—2k

Ω, 10kΩ, 50kΩ

• Resolution: 64 taps each pot

• 20 Ld plastic DIP and 20 Ld SOIC packages

• Pb-free plus anneal available (RoHS compliant)

DESCRIPTION

The X9221A integrates two digitally controlled potenti-

ometers (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 2-wire

bus interface. Each potentiometer has associated with

it a volatile Wiper Counter Register (WCR) and 2 non-

volatile Data Registers (DR0:DR1) 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 con-

tents of DR0 to the WCR.

The XDCP can be used as a three-terminal potentiom-

eter or as a two-terminal variable resistor in a wide

variety of applications including control, parameter

adjustments, and signal processing.

BLOCK DIAGRAM

R1

R0

R3

R2

Wiper

Counter

Register

(WCR)

Register

Array

Pot 1

Wiper

Counter

Register

(WCR)

R1

R0

R3

R2

8

Data

SCL

SDA

A0

A1

A2

A3

Interface

and

Control

Circuitry

Pot 0

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. 2005-2006. All Rights Reserved

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

Data Sheet

FN8163.2

August 30, 2006