74ACT299PC

Overview

The Fairchild Semiconductor 74ACT299PC is an 8-bit universal shift and storage register featuring 3-STATE outputs. It operates within a voltage range of 4.5V to 5.5V and supports four modes: hold, shift left, shift right, and parallel load. The device utilizes multiplexed parallel I/O pins to reduce package count and includes additional serial inputs and outputs for expansion. It provides TTL-compatible inputs and outputs capable of sourcing or sinking 24 mA.

Feature Summary

• Multiplexed parallel input/output data port reduces total pin count
• Four operating modes including shift left, shift right, load, and store
• 3-STATE outputs suitable for bus-oriented applications
• TTL-compatible inputs with high output drive capability

Applications

• Bus-oriented systems requiring bidirectional data transfer
• Parallel-to-serial and serial-to-parallel conversion circuits
• Interface between TTL/NMOS outputs and High-Speed CMOS inputs
• Universal shift registers in digital logic designs

Procurement Notes

Verify the manufacturer designation as Fairchild Semiconductor or its successor entities like onsemi, as corporate acquisitions may affect branding. Confirm the PDIP-20 package type and lead-free status against current RoHS requirements. Check for obsolescence status, as older Fairchild logic parts are frequently discontinued or replaced by newer equivalents from acquired manufacturers.

Selection Notes

Select this component when an 8-bit bidirectional shift register with common parallel I/O is required. Ensure the system voltage aligns with the 4.5V to 5.5V specification. Consider the 24 mA output drive if interfacing with heavy loads. Verify that the multiplexed pin architecture fits the PCB layout constraints compared to devices with dedicated parallel inputs.

Part Context

This part belongs to the 74ACT series of high-speed silicon-gate CMOS logic devices. It is functionally compatible with other 74ACT299 variants from different manufacturers, such as Texas Instruments or NXP, provided pinouts match. It serves as a standard solution for 8-bit data storage and shifting in industrial and consumer electronics.

Replacement Considerations

Public confirmed substitutes include 74ACT299MTC (Fairchild), KK74ACT299 (Kodenshi), and 74F299PCQR (Rochester Electronics). Verify pin compatibility before substitution.