1

®

X9400

Low Noise/Low Power/SPI Bus

Quad Digitally Controlled Potentiometers

(XDCP™)

FEATURES

• Four potentiometers per package

• 64 resistor taps

• SPI serial interface for write, read, and transfer

operations of the potentiometer

• Wiper resistance, 40

Ω typical at 5V.

• Four non-volatile data registers for each

potentiometer

• Non-volatile storage of multiple wiper position

• Power-on recall. Loads saved wiper position on

power-up.

• Standby current < 1µA max

•10k

Ω, 2.5kΩ End to end resistance

• 100 yr. data retention

• Endurance: 100,000 data changes per bit per

register

• Low power CMOS

• 24-lead SOIC and 24-lead TSSOP

DESCRIPTION

The

X9400

integrates

four

digitally

controlled

potentiometers (XDCPs) on a monolithic CMOS

integrated circuit.

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

serial

bus

interface.

Each

potentiometer

has

associated with it a volatile Wiper Counter Register

(WCR) and four nonvolatile Data Registers (DR0-3)

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

Interface

and

Control

Circuitry

CS

SCK

SO

A0

A1

R0 R1

R2 R3

Wiper

Counter

Register

(WCR)

Resistor

Array

Pot 1

R0 R1

R2 R3

Wiper

Counter

Register

(WCR)

Data

8

R0 R1

R2 R3

Resistor

Array

R0 R1

R2 R3

Resistor

Array

Wiper

Counter

Register

(WCR)

Wiper

Counter

Register

(WCR)

Pot 3

Pot 2

HOLD

Pot 0

WP

SI

V+

V-

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

1-888-INTERSIL or 1-888-352-6832

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.

Data Sheet

FN8189.1

March 31, 2005