Datasheet

ManualsBrandsMAXIM INTEGRATED ManualsDiodesMAX366EPA+

_______________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 100Ω 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

♦ ±40V Overvoltage Protection

♦ Open Signal Paths with Power Off

100Ω Signal Paths with Power On

♦ 1nA Max Path Leakage at +25°C

♦ 44V Maximum Supply Voltage Rating

♦ Automatic Protection; No Programming or

Controls

______________Ordering Information

MAX366/MAX367

Signal-Line Circuit Protectors

________________________________________________________________

Maxim Integrated Products

MAX366

OUT1

SENSITIVE

AMPLIFIER

FAULT!

IN1

(SHORT)

(OPEN)

REMOTE SENSOR

ELECTRONICS

+28V

+12V

OUT22 IN2 6

OUT33 IN3 5

V+

V-

PROTECTOR

+10V REG.

___________________________________________________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

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.

* Dice are tested at T

= +25°C only.

* Contact factory for availability.

Summary of content (12 pages)

PAGE 1
9-0326; Rev 0; 12/94 Signal-Line Circuit Protectors ____________________________Features ♦ ±40V Overvoltage Protection ♦ Open Signal Paths with Power Off 100Ω Signal Paths with Power On ♦ 1nA Max Path Leakage at +25°C ♦ 44V Maximum Supply Voltage Rating ♦ Automatic Protection; No Programming or Controls ______________Ordering Information PART† TEMP.
PAGE 2
MAX366/MAX367 Signal-Line Circuit Protectors ABSOLUTE MAXIMUM RATINGS V+ to V-......................................................................-0.3V, +44V IN_, OUT_ ..................................................(V- + 44V), (V+ - 44V) Continuous Current into Any Terminal..............................±30mA Peak Current into Any Terminal (pulsed at 1ms, 10% duty cycle)...................................±70mA Continuous Power Dissipation (TA = +70°C) 8-Pin Plastic DIP (derate 9.09mW/°C above +70°C) ..
PAGE 3
Signal-Line Circuit Protectors TRANSFER CHARACTERISTICS (BIPOLAR SUPPLIES) V+ = +3V, V- = -3V 5 0 V+ = +5V, V- = -5V -5 V+ = +10V, V- = -10V OUTPUT LOAD = 1MΩ -35 -25 -15 MAX366/7-03 15 V+ = 15V 10 V+ = 10V 5 V+ = 5V 0 -5 0 5 15 25 35 0 5 10 15 20 25 30 35 PATH RESISTANCE vs. INPUT VOLTAGE (BIPOLAR SUPPLIES) PATH RESISTANCE vs.
PAGE 4
____________________________Typical Operating Characteristics (continued) (V+ = +15V, V- = -15V, TA = +25°C, unless otherwise noted.) PATH RESISTANCE vs. INPUT VOLTAGE (SINGLE SUPPLY) PATH RESISTANCE vs. INPUT VOLTAGE (SINGLE SUPPLY) 10M V+ = 10V 1M V+ = 35V V+ = 15V 10k 1k MAX366/7-07 450 PATH RESISTANCE (Ω) V+ = 25V 100k 500 MAX366/7-06 1G 100M PATH RESISTANCE (Ω) V+ = 10V 400 V+ = 15V 350 V+ = 25V 300 250 V+ = 5V 200 V+ = 35V 150 100 100 V+ = 5V 10 Circuit of Fig.
PAGE 5
Signal-Line Circuit Protectors PIN NAME* MAX366 MAX367 1, 2, 3 1, 2, 3 IN1, IN2, IN3 – 4–8 IN4–IN8 FUNCTION Signal Inputs 1, 2, 3 Signal Inputs 4–8 4 9 V- – 10–14 OUT8–OUT4 Negative Supply Voltage Input Signal Outputs 4–8 5, 6, 7 15, 16, 17 OUT3, OUT2, OUT1 Signal Outputs 1, 2, 3 8 18 V+ Positive Supply Voltage Input * Inputs and outputs are names for convenience only; inputs and outputs are identical and interchangeable.
PAGE 6
MAX366/MAX367 Signal-Line Circuit Protectors As long as the signal is within these limits, all three transistors conduct and a low-resistance path is maintained from the IN to OUT pin. (Note that, since the device is symmetrical, IN and OUT pins can be interchanged.) When the signal is beyond the gate threshold of either Q2 or Q1/Q3, the path resistance rises dramatically. When power is off, none of the transistors have gate bias, so the circuit from IN to OUT is open.
PAGE 7
Signal-Line Circuit Protectors Single-Supply Output Operation Single-supply operation is a special case. Signals cannot go to ground, since from 0V to approximately +2V is a fault condition. Extremely Low-Current Operation Figure 3 shows the typical high-impedance transfer characteristics with a 100MΩ load.
PAGE 8
MAX366/MAX367 Signal-Line Circuit Protectors Bipolar Faults The MAX366/MAX367 V+ and V- pins are normally connected to a circuit’s most positive and most negative power supplies. When a circuit has multiple power supplies (such as ±5V and ±12V) and the MAX366/ MAX367 V+ and V- pins are connected to the lower supply, it is possible to have fault conditions on both sides of the signal path at once, if both sides of the switch have paths to higher voltages.
PAGE 9
Signal-Line Circuit Protectors MAX366/MAX367 SWITCHED +5V P 100mV +5V MAX366 V+ 1 IN1 OUT1 7 2 IN2 OUT2 6 3 IN3 OUT3 5 4 A 8 MAX366 100k VIN OP AMP V- 4 IN_ V- OUT_ V+ VOUT 8 V+ ADJUSTABLE ANALOG VOLTAGE V- PATH RESISTANCE = 100mV/A -5V Figure 5. Power-Supply Sequencing Figure 6. Path-Resistance Measuring Circuit Figure 6 shows a circuit that can give reliable results.
PAGE 10
MAX366/MAX367 Signal-Line Circuit Protectors __High-Voltage Surge Suppression These devices are not high-voltage arresters, nor are they substitutes for surge suppressers. In systems that use these forms of protection, however, the MAX366/MAX367 can fill a vital gap. Figure 7 shows a typical circuit. Although the surge suppressers are extremely fast shunt elements, they have very soft current knees.
PAGE 11
Signal-Line Circuit Protectors D E DIM E1 A A1 A2 A3 B B1 C D1 E E1 e eA eB L A3 A A2 L A1 0° - 15° C e B1 eA B eB D1 Plastic DIP PLASTIC DUAL-IN-LINE PACKAGE (0.300 in.) DIM PINS D D D D D D DIM D 0°-8° A 0.101mm 0.004in. e B A1 E C H L SO SMALL OUTLINE PACKAGE (0.150 in.) INCHES MAX MIN 0.200 – – 0.015 0.175 0.125 0.080 0.055 0.022 0.016 0.065 0.045 0.012 0.008 0.080 0.005 0.325 0.300 0.310 0.240 – 0.100 – 0.300 0.400 – 0.150 0.
PAGE 12
MAX366/MAX367 Signal-Line Circuit Protectors ___________________________________________Package Information (continued) DIM D 0°- 8° A e B 0.101mm 0.004in. A1 C L A A1 B C E e H L INCHES MAX MIN 0.104 0.093 0.012 0.004 0.019 0.014 0.013 0.009 0.299 0.291 0.050 0.419 0.394 0.050 0.016 DIM PINS E Wide SO SMALL OUTLINE PACKAGE (0.300 in.) H D D D D D 16 18 20 24 28 INCHES MIN MAX 0.398 0.413 0.447 0.463 0.496 0.512 0.598 0.614 0.697 0.713 MILLIMETERS MIN MAX 2.35 2.65 0.10 0.30 0.35 0.49 0.