_______________General Description

These microprocessor (µP) supervisory circuits reduce

the complexity and number of components required for

power-supply monitoring and battery-control functions

in µP systems. They significantly improve system relia-

bility and accuracy compared to separate ICs or

discrete components.

These devices are designed for use in systems powered

by 3.0V or 3.3V supplies. See the selector guide in the

back of this data sheet for similar devices designed for

5V systems. The suffixes denote different reset threshold

voltages: 3.075V (T), 2.925V (S), and 2.625V (R) (see

Reset Threshold section in the Detailed Description). All

these parts are available in 8-pin DIP and SO packages.

Functions offered in this series are as follows:

________________________Applications

Battery-Powered Computers and Controllers

Embedded Controllers

Intelligent Instruments

Automotive Systems

Critical µP Power Monitoring

Portable Equipment

____________________________Features

o

–

R

—

E

—

S

—

E

—

T

–

and RESET Outputs

o Manual Reset Input

o Precision Supply-Voltage Monitor

o 200ms Reset Time Delay

o Watchdog Timer (1.6sec timeout)

o Battery-Backup Power Switching—

o 1µA Battery Supply Current

o Voltage Monitor for Power-Fail or

Low-Battery Warning

o Guaranteed

–

R

—

E

—

S

—

E

—

T

–

o 8-Pin DIP and SO Packages

______________Ordering Information

Ordering Information continued on last page.

* Contact factory for dice specifications.

** These parts offer a choice of reset threshold voltage. Select

the letter corresponding to the desired nominal reset threshold

voltage (T = 3.075V, S = 2.925V, R = 2.625V) and insert it into

the blank to complete the part number.

3.0V/3.3V Microprocessor Supervisory Circuits

________________________________________________________________

Maxim Integrated Products

1

MAX690T/S/R

MAX802T/S/R

MAX804T/S/R

MAX805T/S/R

0.1

µF

RESET

(RESET)

PFO

WDI

R1

VBATT

GND

GND

GND

0.1

µF

0.1

µF

3.6V

LITHIUM

BATTERY

CMOS RAM

µP

RESET

NMI

I/O LINE

UNREGULATED

DC

REGULATED +3.3V OR +3.0V

R2

BUS

( ) ARE FOR MAX804T/S/R, MAX805T/S/R

PFI

See last page for MAX704T/S/R, MAX806T/S/R.

__________________Pin Configuration

1

2

3

4

8

7

6

5

DIP/SO

TOP VIEW

PFO

VBATT

RESET (RESET)

WDI

GND

PFI

MAX690T/S/R

MAX704T/S/R

MAX802T/S/R

MAX804T/S/R

MAX805T/S/R

MAX806T/S/R

( ) ARE FOR MAX804T/S/R, MAX805T/S/R

_________Typical Operating Circuits

Call toll free 1-800-998-8800 for free samples or literature.

19-0243; Rev 1; 9/94

PART**

TEMP. RANGE

MAX690_CPA

0°C to +70°C

MAX690_CSA

0°C to +70°C

MAX690_C/D

0°C to +70°C

Dice*

8 SO

8 Plastic DIP

PIN-PACKAGE

Part

MAX690_EPA

-40°C to +85°C

MAX690_ESA

-40°C to +85°C

MAX690_MJA

-55°C to +125°C

8 CERDIP

8 SO

8 Plastic DIP

MAX690





±4%



±75mV

MAX704





±4%



±75mV

MAX802





±2%



±2%

MAX804





±2%



±2%

MAX805





±4%



±75mV

MAX806





±2%



±2%