74FCT821ASC

Overview

The 74FCT821ASC is a 10-bit bus driver manufactured by National Semiconductor, belonging to the FCT logic series. It features true outputs and operates with CMOS technology in a 20-pin small outline package (SOIC). The device supports unidirectional data transfer with a maximum operating frequency of 83.3 MHz at nominal supply voltage. It has a load capacitance specification of 50 pF and a maximum output current of 64 mA. The component is designed for high-speed digital applications requiring reliable bus interfacing capabilities.

Feature Summary

• Provides 10-bit unidirectional bus driving capability with true output polarity
• Features power-off disabled outputs to prevent floating states during power loss
• Supports high-speed operation up to 83.3 MHz with low load capacitance

Applications

• High-speed data bus interfaces
• Memory bus architectures
• Digital signal processing systems

Procurement Notes

Verify manufacturer authenticity as National Semiconductor assets were acquired. Confirm package type matches SOIC-20 specifications. Check RoHS compliance status as original parts may be non-compliant. Ensure pinout compatibility with target PCB layout. Validate electrical parameters against current design requirements.

Selection Notes

Select this component for applications requiring 10-bit wide bus transfers with high speed. Consider the 20-pin SOIC package for space-constrained designs. Evaluate the 83.3 MHz frequency limit against system clock requirements. Verify power supply voltage compatibility with existing circuitry. Assess thermal performance within the operating temperature range.

Part Context

The 74FCT821ASC belongs to the Fast CMOS (FCT) logic family developed for high-performance digital systems. It serves as a bridge between standard TTL/CMOS logic levels and faster bus architectures. The device replaces older 74F series components with improved speed and drive capabilities while maintaining pin compatibility with similar function devices in the same package.

Replacement Considerations

• CD74FCT821E