DS3668N

Overview

The DS3668N is a quad peripheral driver featuring fault-protected outputs designed for high breakdown voltage and low output ON voltage applications. It provides independent protection on each channel, shutting off an output if load current exceeds approximately 1.0A for more than 12 µs. Each output can sink up to 600 mA with a 70V breakdown capability. The device utilizes TTL-compatible inputs with extremely low input current (1 µA typical), allowing direct drive from MOS devices. It operates on a standard 5V supply and includes internal clamp diodes for inductive fly-back protection.

Feature Summary

• Independent fault protection circuitry on each output prevents latch-up and shuts down channels during overcurrent conditions without affecting other outputs.
• High impedance TTL compatible inputs allow direct driving by MOS devices while maintaining minimal input current requirements.
• Integrated on-chip clamp diodes at each output provide inductive fly-back protection for inductive loads.

Applications

• Relay drivers
• Solenoid drivers
• Stepping motor drivers
• Triac drivers
• Level translators

Procurement Notes

Verify the manufacturer lineage as the datasheet originates from National Semiconductor, which was acquired by Texas Instruments. Confirm that the specific ordering suffix 'N' corresponds to the 16-pin Dual-In-Line package (NS Package Number N16E). Ensure the component meets the required operating temperature range of -40°C to +125°C for your specific application environment before finalizing procurement.

Selection Notes

Select this component when high voltage isolation (70V) and individual channel fault protection are required for peripheral control. It is suitable for driving inductive loads directly due to integrated clamp diodes, provided the voltage is clamped to 35V or less to prevent latch-up. Consider the 600mA per output sinking capability and the 2W power dissipation rating in the molded DIP package when designing thermal management solutions.

Part Context

The DS3668N is part of the DS3668 family of quad peripheral drivers. It serves as a pin-for-pin compatible replacement for the SN75437. The device is housed in a standard 16-pin Dual-In-Line package specifically constructed with a copper lead frame to enhance power dissipation capabilities compared to conventional packages.

Replacement Considerations

The SN75437 is explicitly documented as a pin-for-pin compatible alternative within the same product family.

FAQ

How does the fault protection mechanism reset?

The protection circuitry resets by toggling the corresponding input or by pulling the enable pin low for at least 1.0 µs.

What is the maximum recommended voltage for inductive loads?

For inductive loads, the output should be clamped to 35V or less to avoid latch-up during turn-off, despite the device's 70V breakdown rating.

Can the DS3668N be driven directly by a MOS device?

Yes, its extreme low input current allows it to be driven directly by a MOS device due to its high impedance TTL compatible inputs.