1

© 2001 by Catalyst Semiconductor, Inc.

Characteristics subject to change without notice

Advance Information

FEATURES

Voltages in DAC-like Applications

APPLICATIONS

Calibrating and Adaptive Control systems.

DESCRIPTION

The CAT523 is a dual, 8-bit digitally-programmable

potentiometer configured for programmable voltage and

DAC-like applications. Intended for final calibration of

products such as camcorders, fax machines and cellular

telephones on automated high volume production lines,

it is also well suited for systems capable of self

calibration, and applications where equipment which is

either difficult to access or in a hazardous environment,

requires periodic adjustment.

The 2 independently programmable DPPs have a

common output voltage range which

includes both

supply rails. The wipers are buffered by rail to rail OP

AMPS. Wiper settings, stored in non-volatile memory,

are not lost when the device is powered down and are

automatically reinstated when power is returned. Each

wiper can be dithered to test new output values without

effecting the stored settings and stored settings can be

read back without disturbing the DAC’s output.

Control of the CAT523 is accomplished with a simple 3

wire serial interface. A Chip Select pin allows several

CAT523's to share a common serial interface and

communication back to the host controller is via a single

serial data line thanks to the CAT523’s Tri-Stated Data

Output pin. A RDY/

BSY output working in concert with

an internal low voltage detector signals proper operation

of non-volatile Erase/Write cycle.

The CAT523 is available in the 0 to 70

° C Commercial

and –40

° C to + 85° C Industrial operating temperature

ranges and offered in 14-pin plastic DIP and SOIC

mount packages.

FUNCTIONAL DIAGRAM

PIN CONFIGURATION

CAT523

Configured Digitally Programmable Potentiometer (DPP): Programmable Voltage Applications

DIP Package (P)

SOIC Package (J)

CAT523

Doc. No. 25076-00 2/98 M-1

RDY/

BSY

CLK

CS

PROG

DI

DO

VDD

2

3

4

13

12

11

5

6

7

10

9

8

114

GND

VREFH

VOUT1

VOUT2

VREFL

CLK

CS

PROG

DI

DO

VDD

2

3

4

13

12

11

5

6

7

10

9

8

114

GND

VREFH

VOUT1

VOUT2

VREFL

CAT

523

CAT

523

RDY/

BSY

NC

NC

NC

NC

RDY/BSY

PROG

PROGRAM

CONTROL

DI

CS

CLK

SERIAL

CONTROL

SERIAL

DATA

OUTPUT

REGISTER

GND

V

DD

14

7

5

2

4

V

1

13

12

OUT

OUT

V

2

6

DO

8

9

31

DATA

REGISTER

AND

NONVOLATILE

MEMORY

+

+

V

REFH

V

L

REF

7K

Ω

7K

Ω