SN74ALS621ANG4

Buffers, Drivers, Receivers, Transceivers Overview

The SN74ALS621ANG4 is an octal bus transceiver from the Texas Instruments ALS logic family, housed in a 20-pin plastic DIP (N) package. It features open-collector true outputs and operates within a supply voltage range of 4.5 V to 5.5 V. The device supports asynchronous two-way communication between data buses with dual output-enable inputs for flexible timing control. Recommended operating conditions specify a low-level output current of 24 mA and a high-level output leakage current of 0.1 mA at 5.5 V. Switching characteristics indicate propagation delays ranging from 5 ns to 33 ns depending on the signal path.

Buffers, Drivers, Receivers, Transceivers Feature Summary

• Provides asynchronous two-way communication capability between data buses
• Features open-collector true outputs suitable for wired-OR configurations
• Dual-enable configuration allows data storage by simultaneously enabling both directions

Buffers, Drivers, Receivers, Transceivers Applications

• Asynchronous two-way communication between data buses
• Bus-oriented memory and register implementations
• Control-function implementation requiring maximum flexibility in timing

Buffers, Drivers, Receivers, Transceivers Procurement Notes

Verify that the ordering suffix 'G4' corresponds to lead-free packaging and RoHS compliance as indicated in the manufacturer's package option addendum. Confirm the specific package type matches the required PCB footprint, as this part number designates the standard plastic DIP variant. Ensure the application environment remains within the specified 0°C to 70°C operating temperature range.

Buffers, Drivers, Receivers, Transceivers Selection Notes

Select this component when open-collector outputs are required for bus line driving or wired-logic applications. The ALS series offers a balance of speed and power consumption compared to standard TTL. Verify that the system voltage stays within the 4.5 V to 5.5 V range and that the load capacitance does not exceed the recommended 50 pF for specified switching times.

Buffers, Drivers, Receivers, Transceivers Part Context

This device belongs to the SN74ALS62xA series of octal bus transceivers. It shares functional similarities with the SN74ALS620A (inverting) and SN74ALS623A (three-state), differing primarily in output structure. The ALS technology provides faster switching speeds than standard 74LS devices while maintaining lower power dissipation than older bipolar families.

Buffers, Drivers, Receivers, Transceivers Replacement Considerations

SN74ALS621AN serves as the direct PDIP equivalent without the G4 suffix.