MC74ACT640MEL

Overview

The MC74ACT640MEL is an octal bus transceiver from the onsemi ACT logic series, housed in a 20-pin SOIC-J surface-mount package. It operates within a supply voltage range of 4.5 V to 5.5 V and features inverted outputs with three-state capability. The device provides bidirectional data transfer controlled by direction and enable signals. Key electrical characteristics include a maximum propagation delay of 10 ns at 50 pF load, with output drive currents of ±24 mA. It supports TTL input levels and CMOS output levels, functioning reliably across an industrial temperature range of -40 °C to +85 °C.

Feature Summary

• Octal configuration providing eight independent bidirectional data channels for high-density bus interfacing.
• Three-state outputs allow direct connection to system buses without additional buffering or latching hardware.
• ACT technology ensures fast switching speeds with low power consumption compared to standard TTL equivalents.
• Inverted polarity design facilitates logical signal inversion during data transmission between different circuit domains.

Applications

• High-speed data acquisition systems requiring isolated bidirectional communication paths.
• Memory interface circuits connecting microprocessors to storage arrays.
• Industrial control networks utilizing standard logic families for signal translation.
• Communication gateways managing data flow between peripheral devices and central processing units.

Procurement Notes

Verify the specific suffix MEL against official onsemi documentation to confirm package type and tape-and-reel specifications. Ensure compatibility with existing PCB footprints for SOIC-J-20 packages. Check for RoHS compliance status and lead-free material declarations relevant to your manufacturing region. Confirm availability through authorized distributors as this component may have limited stock or obsolescence notices.

Selection Notes

Select this component when designing systems requiring robust bidirectional data transfer with moderate speed requirements. The ACT series offers a balance of performance and power efficiency suitable for general-purpose logic applications. Consider the inverted output characteristic when mapping signal paths to ensure correct logical operation. Verify that the 5V operating voltage aligns with the rest of the system's power distribution network.

Part Context

This part belongs to the widely adopted 74ACT family of integrated circuits, known for compatibility with standard TTL inputs while offering CMOS noise immunity. The MC74ACT640 variant specifically addresses applications needing multiple parallel data lines. Its SOIC-J package allows for compact board layouts in space-constrained electronic designs. The ACT series remains a staple in legacy and modern mixed-signal systems requiring reliable logic interfacing.

Replacement Considerations

Cross-reference with MC74ACT640DWR2G for similar SOIC-20 packaging and electrical characteristics. Evaluate MC74ACT640NG if through-hole DIP packaging is required instead of surface mount. Verify pinout compatibility before substituting to prevent circuit damage. Consult manufacturer datasheets for any updates in propagation delay or current drive capabilities.