74HCT646DB,118

Overview

The 74HCT646DB,118 is an octal bus transceiver and register manufactured by NXP USA Inc. It features a 24-pin SSOP package and operates within a supply voltage range of 4.5 V to 5.5 V. The device provides non-inverting transmission with three-state outputs for eight-bit data transfer. It integrates latching functionality to hold data states independently of input changes. This component belongs to the HCT logic family, ensuring compatibility with standard TTL-driven systems while maintaining low power consumption characteristics typical of CMOS technology.

Feature Summary

• Octal bus transceiver with integrated register capability
• Three-state output configuration for efficient bus management
• Non-inverting signal transmission path
• Data latching function to maintain state stability

Applications

• Bidirectional data bus interfacing in digital systems
• Memory address and data bus buffering
• I/O expansion modules requiring latched data paths
• System architecture designs utilizing 8-bit parallel communication

Procurement Notes

Verify component authenticity through official manufacturer channels or authorized distributors. Confirm the specific suffix '118' corresponds to the required tape-and-reel packaging format if applicable. Check current lifecycle status as this part may be obsolete or subject to last-time buy restrictions. Ensure RoHS compliance documentation matches project requirements. Validate pinout compatibility with existing PCB footprints before procurement.

Selection Notes

Select this component when an octal transceiver with simultaneous latching is required for 5V logic applications. The HCT series ensures direct interface with TTL inputs without level shifting. Consider the SSOP package constraints regarding thermal dissipation and board space. Verify that the three-state control signals align with the system's bus arbitration logic. Evaluate propagation delay specifications against the maximum clock frequency of the target application.

Part Context

This device is part of the widely adopted 74HCT logic family, designed for high-speed CMOS operation with TTL-compatible inputs. The 74HCT646 specifically addresses applications needing both transmission and storage of eight-bit words on a shared bus. It serves as a critical interface element between microprocessors and peripheral devices or memory arrays in embedded control systems.

Replacement Considerations

Public records indicate the 74HCT646DB,118 is obsolete and no longer manufactured. Designers should consult official replacement guides for equivalent active parts from NXP or other vendors offering compatible octal bus transceivers with latching functions in similar packages.