CD74HC640M

Overview

The CD74HC640M is an octal inverting bus transceiver manufactured by Harris Corporation, belonging to the HC logic series. It features eight independent channels with three-state outputs and operates within a supply voltage range of 2 V to 6 V. The device provides low-level output current of 7.8 mA and high-level output current of -7.8 mA. Propagation delay is specified at 90 ns. It functions with CMOS input and output levels and supports a maximum power supply current of 8 uA. The component is housed in a 20-pin SOIC package and is rated for operation between -55°C and +125°C.

Feature Summary

• Octal configuration providing eight independent bidirectional data paths
• Inverting polarity functionality for signal direction control
• Three-state output capability enabling system bus isolation

Applications

• High-speed data acquisition systems requiring isolated bus interfaces
• Memory mapping applications involving address and data line buffering
• Complex digital systems utilizing multiple parallel data transfers

Procurement Notes

Verify manufacturer origin as Harris Corporation rather than Texas Instruments, noting historical production transitions. Confirm RoHS compliance status through official documentation, as some sources indicate non-compliance. Ensure the specific suffix matches the required package type and temperature rating. Validate that the component meets the intended operating voltage and speed requirements for the target application design.

Selection Notes

Select this component when an octal inverting transceiver with wide voltage tolerance is required. The HC series offers compatibility with standard CMOS logic families. Consider the propagation delay and drive strength for timing-critical designs. Verify availability from authorized distributors given the component's age and potential obsolescence status in certain markets.

Part Context

This part belongs to the CD74HC640 family of bus transceivers. It serves as a bridge between different logic domains or isolates buses in complex digital architectures. The device facilitates efficient data transfer across multiple lines while maintaining signal integrity through its three-state output structure.

Replacement Considerations

Check for direct equivalents such as the SN74HC640 or other octal inverting transceivers from compatible manufacturers. Ensure pinout compatibility and electrical specifications match before substitution.