MC74AC257D

Overview

The MC74AC257D is a quad 2-input multiplexer with 3-state outputs manufactured by onsemi. It belongs to the 74AC logic series and operates within a supply voltage range of 2V to 6V. The device features four independent circuits, each selecting data from two sources using a common select input. Outputs present selected data in true form and can be switched to high impedance via an output enable input. It is housed in a 16-SOIC package.

Feature Summary

• Quad 2-input multiplexer architecture with common data select control
• Noninverting 3-state outputs for direct bus-oriented system interfacing
• Outputs capable of sourcing and sinking 24 mA current

Applications

• Bus-oriented system data routing
• Multiplexer expansion by tying outputs together
• General-purpose digital signal selection

Procurement Notes

Verify component authenticity through authorized channels as counterfeit logic ICs exist. Confirm RoHS compliance status and specific packaging type (tube vs. tape) against the datasheet before procurement. Check for obsolescence notices or product change notifications that may affect long-term availability or pin compatibility.

Selection Notes

Select this component when a quad 2-to-1 multiplexer with 3-state capability is required. Ensure the operating voltage range of 2V to 6V matches the system power supply. Verify that the 16-SOIC surface mount package fits the PCB footprint constraints and thermal requirements.

Part Context

This part is part of the MC74AC257 family, which includes variants like the MC74ACT257. While functionally similar, the ACT variant offers TTL-compatible inputs and different electrical characteristics compared to the standard AC series. The MC74AC257D specifically denotes the SOIC-16 package version of the AC series device.

Replacement Considerations

MC74AC257DR2G: Same functional specifications but supplied in tape and reel packaging instead of tubes.