74FCT821BSC

Overview

The National Semiconductor 74FCT821BSC is a 10-bit bus driver from the FCT series, housed in a 24-pin SOIC package. It features true outputs and operates with a CMOS technology. The device supports a maximum frequency of 83.3 MHz at nominal supply voltage and has a load capacitance of 50 pF. It provides a maximum output current of 64 mA and includes power-off disable functionality for outputs.

Feature Summary

• Provides 10-bit unidirectional data buffering with true output polarity
• Features power-off disabled outputs to prevent floating states during low-power modes
• Supports high-speed operation up to 83.3 MHz with 50 pF load capacitance

Applications

• High-speed data bus interfacing in computer systems
• Buffering address and data lines in memory architectures
• Signal distribution in industrial control networks

Procurement Notes

Verify the manufacturer origin as National Semiconductor or its successors, noting that part numbers may have been transferred to other entities like Texas Instruments. Confirm the package type is strictly 24-pin SOIC and check for RoHS compliance status if required by your assembly process. Ensure the datasheet matches the specific suffix BSC for pinout and electrical characteristics.

Selection Notes

Select this component when a 10-bit wide bus interface is required with high drive capability. The FCT series offers compatibility with standard TTL and CMOS logic levels. Consider the 24-pin SOIC package for surface-mount assembly needs. Verify that the 64 mA output current meets the fan-out requirements of the connected loads.

Part Context

This part belongs to the FCT (Fast CMOS) family, designed for high-speed digital applications. It serves as a buffer/driver within the broader logic IC category. Similar parts include the 74FCT821 variants from other manufacturers like IDT or Pericom, which share functional specifications but may differ in packaging or minor electrical parameters.

Replacement Considerations

Cross-reference with IDT74FCT821DTL or PI74FCT821CTR for functional equivalents. Verify pin compatibility and electrical specifications before substitution. Note that some alternatives may have different package types or lead-free certifications.