TLF5822

April 1990

DS3686 Dual Positive Voltage Relay Driver

General Description

The DS3686 is a high voltagecurrent positive voltage relay

driver having many features not available in present relay

drivers

PNP inputs provide both TTLLS compatibility and high in-

put impedance for low input loading

Output leakage is specified over temperature at an output

voltage of 54V Minimum output breakdown (aclatch break-

down) is specified over temperature at 5 mA This clearly

defines the actual breakdown of the device since the circuit

has incorporated in it an internal reference which does not

allow output breakdown latching found in existing relay driv-

ers Additionally this internal reference circuit feature will

eliminate the need in most cases of an external clamping

(inductive transient voltage protection) diode When the out-

put is turned ‘‘OFF’’ by input logic conditions the resulting

inductive voltage transient seen at the output is detected by

an internal zener reference The reference then momentari-

ly activates the output transistor long enough so that the

relay energy is discharged This feature eliminates the need

of external circuit protection components and insures output

transistor protection

The outputs are Darlington connected transistors which al-

levelsbase drive for the output transistor is obtained from

the load in proportion to the required loading conditions

The circuit also features output transistor protection if the

ance ‘‘OFF’’ state with the same breakdown levels as when

Features

Y

TTLLSCMOS compatible inputs

Y

High impedance inputs (PNP’s)

Y

High output voltage breakdown (65V typ)

Y

High output current capability (300 mA max)

Y

Internal protection circuit eliminates need for output

protection diode

Y

Y

‘‘ON’’)

Y

Voltage and current levels compatible for use in tele-

phone relay applications

Connection Diagrams

Metal Can Package

TLF5822 – 1

Top View

Pin 4 is in electrical contact with the case

Order Number DS3686H

See NS Package Number H08C

Truth Table

A

B

Output X

00

1

10

1

01

1

11

0

Logic ‘‘0’’ output ‘‘ON’’

Logic ‘‘1’’ output ‘‘OFF’’

Dual-In-Line Package

TLF5822 – 2

Top View

Order Number DS3686J-8 or DS3686N

See NS Package Number J08A or N08E

C1995 National Semiconductor Corporation

RRD-B30M105Printed in U S A