SN74F657DW

Buffers, Drivers, Receivers, Transceivers Overview

The SN74F657DW is an octal transceiver with parity generator/checker and 3-state outputs manufactured by Texas Instruments. It combines the functions of the SN74F245 and SN74F280B in a single package. The device operates within a supply voltage range of 4.5 V to 5.5 V and supports an operating temperature range of 0°C to 70°C. It features high-impedance N-P-N inputs, reducing loading effects. The B port outputs provide high drive capability, sinking up to 64 mA and sourcing up to 15 mA. The A port sinks up to 24 mA. Propagation delays are specified at 7.5 ns maximum for data paths and 16 ns maximum for parity generation.

Buffers, Drivers, Receivers, Transceivers Feature Summary

• Integrates bidirectional octal bus transceiver functionality with an 8-bit parity generator and checker circuit.
• Features high-output drive capabilities with distinct current sinking specifications for A and B ports.
• Includes dedicated error output pin that signals parity mismatch during receive mode based on ODD/EVEN selection.

Buffers, Drivers, Receivers, Transceivers Applications

• Bus-oriented applications requiring bidirectional data transfer
• Systems utilizing parity checking for data integrity verification
• Memory interface circuits combining buffering and error detection

Buffers, Drivers, Receivers, Transceivers Procurement Notes

Verify the specific ordering suffix matches the required package type and moisture sensitivity level. Confirm RoHS compliance status and lead finish details against the latest Package Option Addendum. Ensure the active production status aligns with long-term availability requirements for the design lifecycle.

Buffers, Drivers, Receivers, Transceivers Selection Notes

Select this component when a combined transceiver and parity checker is needed to reduce board space. Compare propagation delay specifications against system timing requirements. Evaluate the high-current sink capability of the B port against load conditions. Consider the 3-state output control via the OE input for bus arbitration needs.

Buffers, Drivers, Receivers, Transceivers Part Context

This part belongs to the SN74F logic family, characterized by high-speed operation. It serves as a functional equivalent to separate buffer and parity chip combinations. The DW package denotes a plastic small-outline package variant suitable for surface-mount assembly.

Buffers, Drivers, Receivers, Transceivers Replacement Considerations

Direct substitutes include the SN74F245 for transceiver functions and SN74F280B for parity generation if implemented separately. Verify pin compatibility and electrical characteristics before substitution.