DS3668

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 10A (approximately) on any out-put for more than a built-in delay time nominally 12 s that output will be shut off by its protectioncir cuitry 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 10 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's 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 DS3668 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