MC74ACT157DG

Overview

The MC74ACT157DG is a high-speed quad 2-input multiplexer manufactured by onsemi. It selects four bits of data from two sources using common Select and Enable inputs, presenting the selected data in true form. The device operates within a supply voltage range of 4.5 V to 5.5 V. Propagation delays are specified at 9.0 ns maximum (S to Zn) and 8.5 ns maximum (In to Zn) at 5.0 V with 50 pF load. Outputs source and sink 24 mA. Inputs are TTL compatible.

Feature Summary

• TTL-compatible inputs for direct interfacing with TTL logic systems
• Quad 2-input multiplexing capability with common select and enable controls
• High-speed operation suitable for fast digital signal routing
• Outputs capable of sourcing and sinking 24 mA current

Applications

• Moving data between two groups of registers to common output buses
• Function generation implementing gating functions
• Digital signal selection in microprocessor-based systems

Procurement Notes

Verify the specific ordering suffix 'DG' corresponds to the SOIC-16 package configuration required for your PCB layout. Confirm that the lead-free marking aligns with environmental compliance standards applicable to your manufacturing region. Ensure the component meets the temperature range specifications for your intended operational environment before finalizing procurement.

Selection Notes

Select this component when TTL input compatibility is required alongside AC speed performance. The MC74AC157 serves as the non-TTL variant; choose the ACT version specifically for interfaces requiring standard TTL voltage thresholds. Verify that the 5V supply constraint fits within your system's power distribution architecture.

Part Context

This part belongs to the MC74AC157/74ACT157 family of quad multiplexers. It shares functional similarities with other 74-series logic devices but is distinguished by its specific ACT series characteristics, including TTL input levels. The DG suffix indicates surface-mount packaging in a small outline integrated circuit format.

Replacement Considerations

MC74AC157DG

FAQ

What is the difference between MC74AC157 and MC74ACT157?

The primary difference is input compatibility. The MC74ACT157 features TTL-compatible inputs, whereas the MC74AC157 does not.

How does the Enable input function?

The Enable input is active-LOW. When HIGH, all outputs are forced LOW regardless of other inputs. When LOW, the device operates normally based on the Select input.