SN74HC640NS

Buffers, Drivers, Receivers, Transceivers Overview

The SN74HC640NS is an octal bus transceiver from the Texas Instruments HC logic family, housed in a 20-pin PDIP package. It features eight bidirectional channels with inverted outputs and three-state capability. The device operates on a supply voltage range of 2 V to 6 V, supporting CMOS input and output levels. Key electrical parameters include a maximum high-level output current of -7.8 mA and a maximum low-level output current of 7.8 mA. Propagation delay is specified at 190 ns under a 2 V supply with a 150 pF load. The component functions within an operating temperature range of -40 °C to +85 °C.

Buffers, Drivers, Receivers, Transceivers Feature Summary

• Provides bidirectional data transmission across eight independent channels
• Features three-state outputs for effective bus line isolation
• Inverts signal polarity during data transfer between ports

Buffers, Drivers, Receivers, Transceivers Applications

• Bidirectional data communication on system buses
• Memory interface connections
• I/O port expansion circuits

Buffers, Drivers, Receivers, Transceivers Procurement Notes

Verify the specific suffix 'NS' against manufacturer documentation to confirm the exact package variant and tape-and-reel or tube configuration. Ensure the ordering part number matches the required PDIP-20 physical dimensions and pinout specifications for your PCB layout. Confirm compliance requirements such as RoHS status directly with the supplier before finalizing procurement orders.

Buffers, Drivers, Receivers, Transceivers Selection Notes

Select this component when designing systems requiring wide voltage operation between 2 V and 6 V with moderate speed requirements. The HC technology offers lower power consumption compared to legacy LS families while maintaining compatible logic levels. Consider the 190 ns propagation delay at lower voltages when determining maximum bus clock frequencies for your specific application timing constraints.

Buffers, Drivers, Receivers, Transceivers Part Context

This device belongs to the standard 74HC series of high-speed CMOS logic components manufactured by Texas Instruments. It serves as a fundamental building block for digital systems needing isolated bidirectional data paths. The octal configuration allows simultaneous handling of wide data words, making it suitable for parallel data transfer applications in microcontroller and processor-based designs.

Buffers, Drivers, Receivers, Transceivers Replacement Considerations

The SN74HC640N is a verified equivalent part number offering identical functionality in a PDIP-20 package. For surface-mount implementations, the SN74HC640DW provides the same logical operations in a SOIC-20 footprint. Verify pin compatibility and electrical characteristics before substituting any alternative manufacturers' parts.