74HC646D,653

Overview

The 74HC646D,653 is an octal bus transceiver and register manufactured by NXP USA Inc. It features a single circuit with eight channels and non-inverting polarity. The device utilizes CMOS input and output levels with three-state outputs. It operates within a supply voltage range of 2 V to 6 V. The propagation delay is specified at 220 ns. Low-level output current is 7.8 mA, while high-level output current is -7.8 mA. Maximum quiescent current is 8 uA. Operating temperatures range from -40 C to +125 C. The component is housed in an SSOP-24 package.

Feature Summary

• Octal bus transceiver and register functionality
• Three-state output capability
• CMOS compatible input and output levels

Applications

• Data bus interfacing
• Memory mapping
• I/O expansion

Procurement Notes

Verify the specific ordering suffix and manufacturer designation during procurement. Confirm RoHS compliance status and lead times through authorized distributors. Ensure the SSOP-24 package matches the target PCB footprint. Check for obsolescence notices or lifecycle changes before finalizing orders.

Selection Notes

Select this component for applications requiring octal data buffering with latching capabilities. The HC logic family ensures compatibility with standard CMOS interfaces. Verify that the 2 V to 6 V operating voltage aligns with the system power rails. Consider the thermal performance within the specified temperature range for the intended environment.

Part Context

This part belongs to the 74HC series of high-speed CMOS logic devices. It serves as an octal buffer and register, providing both bus driving and data storage functions. The device integrates level shifting and tri-state control for efficient data management in digital systems.

Replacement Considerations

Check for equivalent parts such as the 74HCT646 for TTL-compatible inputs. Verify pinout and electrical specifications against alternative suppliers. Ensure functional equivalence in terms of propagation delay and drive current.