_______________General Description

The MAX378 8-channel single-ended (1-of-8) multiplexer

and the MAX379 4-channel differential (2-of-8) multiplexer

use a series N-channel/P-channel/N-channel structure to

provide significant fault protection. If the power supplies to

the MAX378/MAX379 are inadvertently turned off while

input voltages are still applied,

all channels in the muxes

are turned off, and only a few nanoamperes of leakage cur-

rent will flow into the inputs. This protects not only the

MAX378/MAX379 and the circuitry they drive, but also the

sensors or signal sources that drive the muxes.

The series N-channel/P-channel/N-channel protection

structure has two significant advantages over the simple

current-limiting protection scheme of the industry’s first-

generation fault-protected muxes. First, the Maxim protec-

tion scheme limits fault currents to nanoamp leakage

values rather than many milliamperes. This prevents dam-

age to sensors or other sensitive signal sources. Second,

the MAX378/MAX379 fault-protected muxes can withstand

a

continuous ±60V input, unlike the first generation, which

had a continuous ±35V input limitation imposed by power

dissipation considerations.

All digital inputs have logic thresholds of 0.8V and 2.4V,

ensuring both TTL and CMOS compatibility without requir-

ing pull-up resistors. Break-before-make operation is

guaranteed. Power dissipation is less than 2mW.

________________________Applications

Data Acquisition Systems

Industrial and Process Control Systems

Avionics Test Equipment

Signal Routing Between Systems

____________________________Features

o Fault Input Voltage ±75V with Power Supplies Off

o Fault Input Voltage ±60V with ±15V Power Supplies

o All Switches Off with Power Supplies Off

o On Channel Turns OFF if Overvoltage Occurs on

Input or Output

o Only Nanoamperes of Input Current Under All

Fault Conditions

o No Increase in Supply Currents Due to Fault

Conditions

o Latchup-Proof Construction

o Operates from ±4.5V to ±18V Supplies

o All Digital Inputs are TTL and CMOS Compatible

o Low-Power Monolithic CMOS Design

______________Ordering Information

Ordering Information continued at end of data sheet.

* Contact factory for availability.

**The substrate may be allowed to float or be tied to V+ (JI CMOS).

High-Voltage, Fault-Protected

Analog Multiplexers

________________________________________________________________

Maxim Integrated Products

1

16

15

14

13

12

11

10

9

1

2

3

4

5

6

7

8

A1

A2

GND

V+

IN1

V-

EN

A0

TOP VIEW

MAX378

IN5

IN6

IN7

IN8

OUT

IN4

IN3

IN2

DIP

16

15

14

13

12

11

10

9

1

2

3

4

5

6

7

8

A1

GND

V+

IN1B

IN1A

V-

EN

A0

MAX379

IN2B

IN3B

IN4B

OUTB

OUTA

IN4A

IN3A

IN2A

DIP

__________________________________________________________Pin Configurations

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

19-1902; Rev 1; 8/94

PART

MAX378CPE

MAX378CWG

MAX378CJE

0°C to +70°C

0°C to +70°C

0°C to +70°C

TEMP. RANGE

PIN-PACKAGE

16 Plastic DIP

24 Wide SO

16 CERDIP

MAX378EPE

MAX378EWG

-40°C to +85°C

-40°C to +85°C

16 Plastic DIP

24 Wide SO

MAX378EJE

MAX378MJE

-55°C to +125°C

-40°C to +85°C

16 CERDIP

16 CERDIP

MAX378MLP

-55°C to +125°C

20 LCC*

Pin Configurations continued at end of data sheet.

MAX378C/D

0°C to +70°C

Dice**