SN74HC157D

Overview

The SN74HC157D is a quadruple 2-line to 1-line data selector/multiplexer manufactured by Texas Instruments in a 16-pin SOIC package. It operates within a supply voltage range of 2V to 6V and supports an operating temperature from -40°C to 85°C. The device features four independent multiplexers controlled by a common address select input and an active-low strobe input. Electrical characteristics include a maximum propagation delay of 38ns at 4.5V with 50pF load, output drive capability up to 15 LSTTL loads, and low power consumption with a maximum static current of 160µA.

Feature Summary

• Contains four independent 2-to-1 multiplexers sharing a single address select input for synchronized channel selection
• Features TTL-compatible CMOS inputs allowing direct interfacing with standard logic families
• Includes an active-low strobe input that forces all outputs to a low state regardless of other input conditions

Applications

• Switching a 4-bit data bus between two source devices
• Routing data signals from multiple registers to a common output bus
• Implementing function generators in digital circuits

Procurement Notes

Verify the specific ordering suffix against the latest TI Package Option Addendum to confirm status and packaging details. The base part number SN74HC157D may be obsolete; ensure the selected variant matches the required package type and production status. Confirm RoHS compliance and lead finish specifications during procurement to align with assembly requirements.

Selection Notes

Select this component when a high-speed, low-power quadruple multiplexer is required for general-purpose digital applications. Ensure the design accommodates the specified input transition times to prevent oscillations and excessive power consumption. Verify that the capacitive load does not exceed recommended limits to maintain switching performance specifications.

Part Context

This device belongs to the SNx4HC157 family of high-speed silicon gate CMOS multiplexers. It provides a pin-compatible alternative to older logic families while offering improved speed and lower power dissipation. The D suffix denotes the 16-pin Small Outline Integrated Circuit (SOIC) package format used for surface-mount applications.

Replacement Considerations

SN74HC157DR

FAQ

How does the strobe input affect the outputs?

A high level at the strobe terminal forces all Y outputs low, regardless of the state of the address select or data inputs.

What is the behavior of unused inputs?

Unused inputs must be terminated at VCC or GND to ensure proper operation. Leaving them floating can cause excessive power consumption and oscillations.