X9221

1

© Xicor, Inc. 1994, 1995, 1996 Patents Pending.

Characteristics subject to change without notice

3079-1.6 6/12/96 T1/C1/D0 NS

FEATURES

—Directly Write Wiper Position

—Read Wiper Position

—Store as Many as Four Positions per Pot

—Quick Transfer of Register Contents to

Resistor Array

—Endurance - 100,000 Writes per Register

—Register Data Retention - 100 years

—2K

Advance Information

X9221

DESCRIPTION

controlled potentiometers on a monolithic CMOS micro-

circuit.

The X9221 contains two resistor arrays, each com-

posed of 63 resistive elements. Between each element

and at either end are tap points accessible to the wiper

elements. The position of the wiper element on the array

is controlled by the user through the two-wire serial bus

interface.

Each resistor array has associated with it a wiper counter

register and four 8-bit data registers that can be directly

written and read by the user. The contents of the wiper

counter register control the position of the wiper on the

resistor array.

The data register may be read or written by the user. The

contents of the data registers can be transferred to the

wiper counter register to position the wiper. The current

wiper position can be transferred to any one of its

associated data registers.

FUNCTIONAL DIAGRAM

Terminal Voltage

R0 R1

R2 R3

WIPER

COUNTER

REGISTER

(WCR)

RESISTOR

ARRAY

POT 1

VH1

VL1

VW1

R0 R1

R2 R3

WIPER

COUNTER

REGISTER

(WCR)

INTERFACE

AND

CONTROL

CIRCUITRY

SCL

SDA

A0

A1

A2

A3

VH0

VL0

VW0

DATA

3079 ILL F07.1

8

A V AILABLE

AN20 • AN42 • AN44–48 • AN50 • AN52 • AN53 • AN73