CAT521

© Catalyst Semiconductor, Inc.

1

Doc. No. MD-2003 Rev. G

Characteristics subject to change without notice

Configured Digitally Programmable Potentiometer (DPP™):

Programmable Voltage Applications

FEATURES

8-bit DPP configured as a programmable

voltage source in DAC-like applications

Buffered wiper output

Non-volatile NVRAM memory wiper storage

Output voltage range includes both supply rails

1 LSB accuracy, high resolution

Serial Microwire-like interface

Single supply operation: 2.7V – 5.5V

Setting read-back without effecting outputs

For Ordering Information details, see page 12.

APPLICATIONS

Automated product calibration

Remote control adjustment of equipment

Offset, gain and zero adjustments in self-

calibrating and adaptive control systems

Tamper-proof calibrations

DAC (with memory) substitute

PIN CONFIGURATION

PDIP 14-Lead (L)

SOIC 14-Lead (W)

CLK 2

13 NC

RDY/BSY

¯¯¯¯ 3

CS 4

11 NC

DI 5

10 NC

DO 6

8

PROG 7

8

GND

CAT521

DESCRIPTION

The CAT521 is a 8-bit digitally-programmable poten-

tiometer (DPP™) 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 self-calibrating

systems and for applications where equipment which

requires periodic adjustment is either difficult to access

or in a hazardous environment.

The programmable DPP has an output voltage range

which includes both supply rails. The wiper is buffered

by a rail to rail op amp. The wiper setting, stored in

non-volatile NVRAM memory, is not lost when the

device is powered down and is automatically

reinstated when power is returned. The wiper can be

dithered to test new output values without effecting

the stored settings and stored settings can be read

back without disturbing the DPP’s output.

The CAT521 is controlled with a simple 3-wire,

Microwire like serial interface. A Chip Select pin

allows several devices to share a common serial

interface. Communication back to the host controller is

via a single serial data line thanks to the CAT521 Tri-

Stated Data Output pin. A RDY/BSY

¯¯¯¯ output working in

concert with an internal low voltage detector signals

proper operation of the non-volatile NVRAM memory

Erase/Write cycle.

The CAT521 is available in 0°C to 70°C commercial

and -40°C to 85°C industrial operating temperature

ranges. Both 14-pin plastic DIP and surface mount

packages are available.