DS8921AMX

Overview

The DS8921AMX is a single RS-422 differential line driver and receiver pair manufactured by Texas Instruments, originally from the National Semiconductor portfolio. It operates within a supply voltage range of 4.5 V to 5.5 V, with a typical operating current of 35 mA. The device supports data transmission rates up to 10 Mb/s and functions reliably across an extended temperature range from -40°C to +85°C. Housed in an SOIC-8 surface-mount package, this transceiver integrates one driver and one receiver without a shutdown feature, designed for robust communication in industrial environments.

Feature Summary

• Provides differential signaling capabilities compliant with RS-422 standards for reliable long-distance data transmission.
• Features low skew characteristics to maintain critical system timing integrity during high-speed operations.
• Utilizes CMOS technology to balance performance with manageable power consumption in standard 5V systems.

Applications

• Industrial automation networks requiring robust differential communication links.
• Data acquisition systems needing high noise immunity over moderate distances.
• Embedded control systems utilizing RS-422 serial interfaces.

Procurement Notes

Verify the manufacturer designation carefully, as the component originates from National Semiconductor but is now distributed under the Texas Instruments brand. Confirm the specific suffix 'AMX' corresponds to the required temperature grade and tape-and-reel packaging format. Ensure compatibility with existing PCB footprints for the SOIC-8 package before integration into new designs.

Selection Notes

Select this component when a single-channel RS-422 transceiver is required for applications demanding 10 Mb/s speeds. It is suitable for designs operating strictly on 5V supplies within the commercial/industrial temperature range. Consider alternative packages if lead-free compliance or specific reel quantities are mandatory constraints for the production line.

Part Context

This part belongs to the DS8921x series of high-speed, low-skew RS-422 drivers and receivers. The family addresses timing issues in critical systems through optimized internal circuitry. While the base DS8921 exists, the 'A' variant typically denotes improved specifications or manufacturing revisions, and the 'MX' suffix indicates the specific tape-and-reel packaging configuration used for automated assembly.

Replacement Considerations

Direct functional substitutes include other single RS-422 transceivers such as the SN75179B or SN75ALS181, though pinouts and electrical characteristics must be verified against the original datasheet. Cross-reference with the broader DS8921 family variants to ensure identical package dimensions and thermal performance requirements are met.