_______________General Description

The MAX366 and MAX367 are multiple, two-terminal circuit

protectors. Placed in series with signal lines, each two-ter-

minal device guards sensitive circuit components against

voltages near and beyond the normal supply voltages.

These devices are used at interfaces where sensitive cir-

cuits are connected to the external world and could

encounter damaging voltages (up to 35V beyond the sup-

ply rails) during power-up, power-down, or fault conditions.

The MAX366 contains three independent protectors and

the MAX367 contains eight. They can protect analog sig-

nals using either unipolar (4.5V to 36V) or bipolar (±2.25V

to ±18V) power supplies. Each protector is symmetrical.

Input and output terminals may be freely interchanged.

These devices are voltage-sensitive MOSFET transistor

arrays that are normally on when power is applied and

normally open circuit when power is off. With ±10V sup-

plies, on-resistance is 100

Ω max and leakage is less than

1nA at +25°C.

When signal voltages exceed or are within approximately

1.5V of either power-supply voltage (including when

power is off), the two-terminal resistance increases dra-

matically, limiting fault current as well as output voltage to

sensitive circuits. The protected side of the switch main-

tains the correct polarity and clamps approximately 1.5V

below the supply rail. There are no “glitches” or polarity

reversals going into or coming out of a fault condition.

________________________Applications

Process Control Systems

Redundant/Backup Systems

Hot-Insertion Boards/Systems ATE Equipment

Data-Acquisition Systems

Sensitive Instruments

____________________________Features

o ±40V Overvoltage Protection

o Open Signal Paths with Power Off

100

Ω Signal Paths with Power On

o 1nA Max Path Leakage at +25°C

o 44V Maximum Supply Voltage Rating

o Automatic Protection; No Programming or

Controls

______________Ordering Information

Signal-Line Circuit Protectors

________________________________________________________________

Maxim Integrated Products

1

MAX366

OUT1

SENSITIVE

AMPLIFIER

1

FAULT!

FAULT!

IN1

(SHORT)

(OPEN)

REMOTE SENSOR

ELECTRONICS

7

+28V

+12V

OUT2

2

IN2

6

OUT3

3

IN3

5

V+

4

V-

PROTECTOR

+10V REG.

8

___________________________________________________Typical Operating Circuit

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

19-0326; Rev 0; 12/94

PART†

MAX366CPA

MAX366CSA

MAX366C/D

0°C to +70°C

0°C to +70°C

0°C to +70°C

TEMP. RANGE

PIN-PACKAGE

8 Plastic DIP

8 SO

Dice*

MAX366EPA

MAX366ESA

MAX366MJA

-55°C to +125°C

-40°C to +85°C

-40°C to +85°C

8 Plastic DIP

8 SO

8 CERDIP**

MAX367CPN

MAX367CWN

MAX367C/D

0°C to +70°C

0°C to +70°C

0°C to +70°C

18 Plastic DIP

18 Wide SO

Dice*

MAX367EPN

MAX367EWN

MAX367MJN

-55°C to +125°C

-40°C to +85°C

-40°C to +85°C

18 Plastic DIP

18 Wide SO

18 CERDIP**

Pin Configurations appear at end of data sheet.

† MAX367 available after January 1, 1995.

* Contact factory for availability.