DS3668N/HAPB

Overview

The DS3668N is a quad peripheral driver featuring independent fault protection for each output channel. It provides high breakdown voltage capability of 70V and sinks up to 600 mA per output with a typical low ON voltage of 550 mV at full load. The device incorporates built-in delay circuitry to prevent false triggering from turn-on surge currents, shutting off the affected output if current exceeds approximately 1.4 A for more than 12 µs. Inputs are TTL compatible with minimal current draw, allowing direct drive from MOS devices. An on-chip clamp diode handles inductive fly-back currents up to 800 mA. The component operates on a standard 5V supply within a -40°C to +125°C ambient temperature range.

Feature Summary

• Independent fault protection circuitry isolates output shutdowns without affecting other channels
• High impedance inputs ensure compatibility with TTL logic and direct MOS driving
• Integrated clamp diodes provide inductive load protection against latch-up
• Fail-safe operation maintains high impedance state when inputs are open

Applications

• Relay drivers
• Solenoid drivers
• Stepping motor drivers
• Triac drivers
• Fiber optic LED drivers

Procurement Notes

Verify the manufacturer origin carefully as Texas Instruments acquired National Semiconductor. Confirm that the specific ordering suffix matches the required package type and thermal characteristics. Ensure the datasheet revision aligns with your design requirements. Check for any specific handling instructions related to the molded dual-in-line package construction.

Selection Notes

Select this component for applications requiring high voltage tolerance and individual channel fault isolation. Verify that the 600 mA sink capability meets the peak load requirements. Consider the 70V breakdown limit for inductive loads and ensure external clamping is used if voltages exceed 35V during turn-off. Evaluate the power dissipation limits relative to the expected duty cycle and ambient temperature.

Part Context

Originally manufactured by National Semiconductor, this part was integrated into Texas Instruments' portfolio following their acquisition. The DS3668 serves as a robust solution for driving high-power peripheral loads where reliability under fault conditions is critical. It remains a standard choice for industrial control systems requiring isolated fault management across multiple channels.

Replacement Considerations

The SN75437 is documented as pin-for-pin compatible. Verify electrical specifications and fault threshold timings match before substitution.