74FST3400QSR

Overview

The onsemi 74FST3400QSR is a 4-bit, 4-port bus exchange switch manufactured by Semiconductor Components Industries, LLC. It operates within a supply voltage range of 4.0 to 5.5 volts and features CMOS TTL compatibility. The device provides extremely low on-resistance (RON) with typical values of 4 ohms at 4.5V and maximum propagation delays under 0.25 ns through the switch. It adds negligible standby current and prevents circuit bounce or ground noise. Control inputs are compatible with both TTL and CMOS logic levels.

Feature Summary

• Provides four independent bidirectional bus ports for signal routing and exchange
• Features nearly zero propagation delay and minimal on-resistance for high-speed data transfer
• Eliminates circuit bounce and ground noise during switching operations
• Includes dedicated control pins for individual bit-level bus exchange functionality

Applications

• High-speed bus arbitration systems requiring low-latency signal routing
• Data communication interfaces needing dynamic port configuration
• Digital logic circuits requiring isolated bus segments with exchange capabilities
• System architectures demanding minimal signal degradation during switching

Procurement Notes

Verify that the ordering suffix QSR corresponds specifically to the QSOP-24 package variant. Confirm the component meets RoHS standards if lead-free construction is required for your assembly process. Ensure control inputs are tied to valid logic levels rather than left open to prevent undefined states. Cross-reference the datasheet revision to confirm electrical characteristics match your design requirements.

Selection Notes

Select this component when designing systems requiring simultaneous multi-port bus connectivity with minimal signal delay. The FST series offers superior speed compared to standard CMOS switches. Verify that the operating voltage range aligns with your system's power supply rails. Consider the package dimensions if space constraints exist in your printed circuit board layout.

Part Context

This device belongs to the 74FST logic family, designed for high-speed applications. It serves as a direct pin-for-pin replacement for similar bus switches like the QS3400, FST3400, and CBT3400. The technology combines the speed of ECL-like performance with the low power consumption of CMOS processes. It is suitable for complex digital systems requiring flexible interconnectivity.

Replacement Considerations

Direct substitutes include the QS3400, FST3400, and CBT3400. These components share identical pinouts and functional specifications. Verify that alternative manufacturers meet the same electrical parameters regarding on-resistance and propagation delay before implementation.