1

GND

DAC 2

EEPROM

LATCH

EEPROM

LATCH

11

DAC 1

12

PROG

RDY/

BSY

PROGRAM

CONTROL

H.V.

CHARGE

PUMP

SERIAL DATA OUTPUT

V

2

OUT

10

V

L2

REF

V

H2

REF

V

1

OUT

V

L1

REF

V

H1

REF

DO

DATA

CONTROLLER

13

14

3

CLK

CS

2

4

5

7

9

8

1

6

DI

+

–

+

–

DO

PROG

RDY/BSY

CLK

1

2

3

4

5

6

7

14

13

12

11

8

10

9

VDD

VREF H2

VREF H1

GND

VOUT1

V

OUT

2

CS

DI

VREF L2

VREF L1

DO

PROG

RDY/BSY

CLK

1

2

3

4

5

6

7

14

13

12

11

8

10

9

VDD

VREF H2

VREF H1

GND

VOUT1

V

OUT

2

CS

DI

VREF L2

VREF L1

CAT522

8-Bit Dual Digital POT With Independent Reference Inputs

FEATURES

APPLICATIONS

Calibrating and Adaptive Control systems.

DESCRIPTION

The CAT522 is a dual 8-Bit Memory DAC designed as an

electronic replacement for mechanical potentiometers

and trim pots. Intended for final calibration of products

such as camcorders, fax machines and cellular tele-

phones on automated high volume production lines and

systems capable of self calibration, it is also well suited

for applications were equipment requiring periodic ad-

justment is either difficult to access or located in a

hazardous environment.

The CAT522 offers 2 independently programmable DACs

each having its own reference inputs and each capable

of rail to rail output swing. Outputs are buffered by rail

to rail OP AMPS Output settings, stored in non-volatile

EEPROM memory, are not lost when the device is

powered down and are automatically reinstated when

power is returned. Each output can be dithered to test

new output values without effecting the stored settings

FUNCTIONAL DIAGRAM

PIN CONFIGURATION

and stored settings can be read back without disturbing

the DAC’s output.

Control of the CAT522 is accomplished with a simple 3

wire serial interface. A Chip Select pin allows several

CAT522's to share a common serial interface and com-

munications back to the host controller is via a single

serial data line thanks to the CAT522’s Tri-Stated Data

Output pin. A RDY/

BSY output working in concert with

an internal low voltage detector signals proper operation

of EEPROM Erase/Write cycle.

The CAT522 operates from a single 3–5 volt power

supply. The high voltage required for EEPROM Erase/

Write operations is generated on-chip.

The CAT522 is available in the 0

°C to 70°C Commercial

and –40

°C to +85°C Industrial operating temperature

ranges and offered in 14-pin plastic DIP and Surface

mount packages.

DIP Package (P)

SOIC Package (J)

CAT522

© 2000 by Catalyst Semiconductor, Inc.

Characteristics subject to change without notice

Advanced Information

CAT522

CAT522