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 protected circuit is incorporated on each output. When

the load current exceeds 1.0A (approximately) on any output

for more than a built-in delay time, nominally 12 μs, that

output will be shut off by its protection circuitry with no effect

on other outputs. This condition will prevail until that protection

circuitry is reset by toggling the corresponding input or

the enable pin low for at least 1.0 μs. This built-in delay is

provided to ensure that the protection circuitry is not triggered

by turn-on surge currents associated with certain

kinds of loads.

The DS3668’s inputs combine TTL compatibility with high

input impedance. In fact, its extreme low input current allows

it to be driven directly by a MOS device. The outputs are

capable of sinking 600 mA each and offer a 70V breakdown.

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 incorporates 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

increased 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

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

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 μA typical)

Low operating power

Standard 5V power supply

Power up/down protection

Fail-safe operation

2W power package

Pin-for-pin compatible with SN75437