SN74HC157DR

Overview

The SN74HC157DR is a quadruple 2-line to 1-line data selector/multiplexer housed 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 low input current (1µA max) and typical propagation delay of 11ns at 5V. Outputs can drive up to 15 LSTTL loads with ±6mA drive capability at 5V. Maximum ICC consumption is 80µA.

Feature Summary

• Contains four independent 2-to-1 multiplexers controlled by a common address select input.
• Features TTL-compatible CMOS inputs for direct interfacing with TTL logic devices.
• Includes an active-low strobe input that forces all outputs to a low state regardless of other inputs.

Applications

• Multiplexing and routing 4-bit data buses between two source devices.
• Selecting one of two data sources for processing or transmission.
• Data switching applications requiring asynchronous control via address lines.

Procurement Notes

Verify the specific ordering suffix 'DR' corresponds to the SOIC-16 package and tape-and-reel carrier format. Confirm the operating temperature range (-40°C to 85°C) matches system requirements. Ensure compatibility with the 2V–6V supply voltage range and check for RoHS compliance status indicated by the NIPDAU lead finish. Validate that the device status is listed as Active Production in official TI documentation before procurement.

Selection Notes

Select this component when a quadruple 2-to-1 multiplexer function is required in a compact surface-mount form factor. It is suitable for systems needing TTL-compatible inputs and low power consumption. Consider the 16-pin SOIC package constraints and thermal resistance values if high ambient temperatures are expected. Ensure the application does not require military-grade temperature ranges, which necessitate the SN54 series variants.

Part Context

The SN74HC157 belongs to the Texas Instruments HC (High-speed CMOS) logic family. It is part of the SNx4HC157 series, which includes multiple package options such as SSOP, PDIP, and TSSOP. The 'D' suffix denotes the SOIC package, while 'R' indicates tape-and-reel packaging. This device serves as a standard digital logic solution for data selection tasks in commercial electronics.

Replacement Considerations

SN74HC157DBR: Alternative SSOP-16 package version of the same logical function.

FAQ

How does the strobe input affect the outputs?

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

What happens if CMOS inputs are left floating?

Standard CMOS inputs must not be left floating. Unused inputs should be terminated at VCC or GND to prevent excessive power consumption and potential oscillations.