74AC299MTC

Overview

The onsemi 74AC299MTC is an 8-bit universal shift/storage register housed in a 20-lead TSSOP package. It features edge-triggered D-type flip-flops with common parallel I/O pins to reduce pin count. The device supports four modes: hold, shift left, shift right, and parallel load. Outputs are 3-state for bus-oriented applications. Supply voltage ranges from 2.0V to 6.0V. Operating temperature spans -40°C to +85°C.

Feature Summary

• Supports synchronous shift left, shift right, parallel load, and hold operations via mode select inputs.
• Features common parallel I/O pins that serve as both data inputs and 3-state outputs.
• Includes dedicated serial outputs (Q0, Q7) for easy expansion in serial cascading configurations.
• Provides asynchronous master reset functionality independent of clock or select inputs.

Applications

• Bus-oriented data storage systems requiring tri-state isolation
• Serial-to-parallel and parallel-to-serial data conversion circuits
• Digital signal processing chains utilizing cascaded shift registers

Procurement Notes

Verify the specific suffix 'MTC' confirms the 20-lead Thin Shrink Small Outline Package (TSSOP). Confirm RoHS compliance status through official documentation. Check current production status as legacy AC series parts may have limited availability or obsolescence notices. Ensure supply voltage requirements match the 2.0V to 6.0V range specified for the AC variant.

Selection Notes

Select this component when an 8-bit universal shift register with common I/O is required to minimize pin count. Choose the AC variant over ACT if TTL-compatible inputs are not strictly necessary and lower voltage operation down to 2.0V is desired. Verify that the 3-state output capability meets the bus driving requirements of the target system architecture.

Part Context

This part belongs to the 74AC logic family, known for high-speed CMOS performance. The 74AC299 specifically addresses designs needing flexible data shifting and storage within a compact footprint. It serves as a foundational building block for complex digital state machines and communication interfaces requiring serial data handling capabilities.

Replacement Considerations

Direct substitutes include other manufacturers' 74AC299 equivalents in TSSOP-20 packages. Cross-reference pinouts and electrical characteristics carefully. Note that 74ACT299 variants require 4.5V to 5.5V supply and offer TTL-compatible inputs, differing from the AC input thresholds.