74HCT40105D,112

Overview

The 74HCT40105D,112 is a first-in/first-out elastic storage register manufactured by Nexperia USA Inc. It stores 16 words of 4-bit data and handles input/output at different shifting rates. The device features independent asynchronous inputs and outputs, expandability in either direction, reset capability, status indicators on inputs and outputs, and 3-state outputs. Input levels are TTL compatible for the HCT variant. It complies with JEDEC standard JESD7A and includes ESD protection exceeding 2000 V (HBM) and 200 V (MM). Operating temperature ranges from -40°C to +125°C.

Feature Summary

• Independent asynchronous inputs and outputs
• Expandable in either direction
• Reset capability
• Status indicators on inputs and outputs
• 3-state outputs

Applications

• Buffer between asynchronous systems
• Data rate conversion applications
• Elastic storage registers

Procurement Notes

Verify the manufacturer part number against official Nexperia documentation to ensure authenticity. Confirm that the SO16 package matches system requirements. Check RoHS compliance status as specified in the datasheet. Ensure operating conditions align with recommended limits. Validate pin configuration against schematic designs before integration.

Selection Notes

Select this component when TTL-compatible logic levels are required for FIFO buffering. The HCT variant ensures compatibility with standard TTL inputs while maintaining CMOS performance. Consider the 16-word depth and 4-bit width for moderate buffer needs. Verify thermal derating requirements for the SO16 package if operating above 70°C. Assess expansion capabilities if larger word capacities are needed.

Part Context

This part belongs to the 74HC/HCT40105 series of high-speed Si-gate CMOS devices. It is pin-compatible with the 4000B series 40105. The series includes HC and HCT variants, differing primarily in input voltage levels. The D suffix indicates an SO16 plastic small outline package. Nexperia manufactures these components under license from Philips Semiconductors.

Replacement Considerations

74HC40105D,112

FAQ

What do the DIR and DOR flags indicate?

DIR (Data-In-Ready) HIGH indicates the input stage is empty and ready for data; LOW means full or busy. DOR (Data-Out-Ready) HIGH indicates valid data is present at the outputs; LOW means the output stage is busy or empty.

How is the FIFO expanded?

The FIFO can be expanded in word length using additional logic gates or cascaded to increase word capacity beyond 16 words without external components for timing.