CD74HC640M

Overview

The CD74HC640M is an octal bus transceiver from the Texas Instruments HC logic family, housed in a SOIC-20 package. It features three-state outputs and operates within a supply voltage range of 2 V to 6 V. The device provides a propagation delay of 90 ns and supports low-level output currents of 7.8 mA and high-level output currents of -7.8 mA. It functions as an inverting bus transceiver with eight channels and maintains a maximum power supply current of 8 uA across an operating temperature range of -55 C to +125 C.

Feature Summary

• Octal bidirectional data transmission capability with inverting polarity for signal inversion during transfer.
• Three-state outputs allowing direct connection to bus lines without additional pull-up or pull-down requirements.
• Wide operating voltage range supporting compatibility with various CMOS logic systems.

Applications

• Memory module data bus interfacing
• Microcontroller system I/O expansion
• Bidirectional data gate applications

Procurement Notes

Verify the specific suffix 'M' corresponds to the tube packaging format rather than reel or cut tape options. Confirm the extended industrial temperature rating (-55 C to +125 C) matches the design requirements, distinguishing it from commercial grade variants. Ensure the datasheet version aligns with the manufacturing date code for accurate electrical parameter validation.

Selection Notes

Select this component when an octal width with inverting functionality is required for bus architectures. The HC series offers standard speed suitable for general-purpose digital interfaces. Consider the SOIC-20 footprint constraints and verify that the 90 ns propagation delay meets the timing specifications of the target system clock speeds.

Part Context

This part belongs to the CD74HC640 series of octal bus transceivers manufactured by Texas Instruments. It utilizes CMOS technology to provide efficient power consumption alongside robust noise immunity. The device serves as a standard interface solution for connecting microprocessors to peripheral devices or memory arrays in complex digital circuits.

Replacement Considerations

SN74HC640DWR

FAQ

Is the CD74HC640M inverting or non-inverting?

The CD74HC640M is an inverting bus transceiver, meaning the output signals are logically inverted relative to the input signals.

What is the maximum operating temperature for this device?

The maximum operating temperature for the CD74HC640M is +125 C, indicating it is rated for industrial temperature applications.