DS3668 Quad Fault Protected Peripheral Driver
March 1995
DS3668 Quad Fault Protected Peripheral Driver
General Description
The DS3668 quad peripheral driver is designed for those
applications where low operating power high breakdown
voltage high output current and low output ON voltage are
required Unlike most peripheral drivers available a unique
fault protection circuit is incorporated on each output When
the load current exceeds 1 0A (approximately) on any out-
put for more than a built-in delay time nominally 12
ms
that
output will be shut off by its protection circuitry with no effect
on other outputs This condition will prevail until that protec-
tion circuitry is reset by toggling the corresponding input or
the enable pin low for at least 1 0
ms
This built-in delay is
provided to ensure that the protection circuitry is not trig-
gered by turn-on surge currents associated with certain
kinds of loads
The DS3668鈥檚 inputs combine TTL compatibility with high
input impedance In fact its extreme low input current al-
lows it to be driven directly by a MOS device The outputs
are capable of sinking 600 mA each and offer a 70V break-
down However for inductive loads the output should be
clamped to 35V or less to avoid latch up during turn off
(inductive fly-back protection
refer AN-213) An on-chip
clamp diode capable of handling 800 mA is provided at
each output for this purpose In addition the DS3668 incor-
porates circuitry that guarantees glitch-free power up or
down operation and a fail-safe feature which puts the output
in a high impedance state when the input is open
The molded package is specifically constructed to allow in-
creased power dissipation over conventional packages The
four ground pins are directly connected to the device chip
with a special copper lead frame When the quad driver is
soldered into a PC board the power rating of the device
improves significantly
Applications
Y
Y
Y
Y
Y
Y
Y
Y
Y
Relay drivers
Solenoid drivers
Hammer drivers
Stepping motor drivers
Triac drivers
LED drivers
High current high voltage drivers
Level translators
Fiber optic LED drivers
Features
Y
Y
Y
Y
Y
Y
Y
Y
Y
Y
Y
Y
Y
Y
Y
Output fault protection
High impedance TTL compatible inputs
High output current 600 mA per output
No output latch-up at 35V
Low output ON voltage (550 mV typ
600 mA)
High breakdown voltage (70V)
Open collector outputs
Output clamp diodes for inductive fly-back protection
NPN inputs for minimal input currents (1
mA
typical)
Low operating power
Standard 5V power supply
Power up down protection
Fail-safe operation
2W power package
Pin-for-pin compatible with SN75437
Connection Diagram
Dual-In-Line Package
Truth Table
IN
H
L
H
L
H
e
High state
L
e
Low state
EN
H
H
L
L
OUT
L
Z
Z
Z
Z
e
High impedance state
TL F 5225 鈥?1
Top View
Order Number DS3668N
See NS Package Number N16E
C
1995 National Semiconductor Corporation
TL F 5225
RRD-B30M105 Printed in U S A
1
2
3
4
