SN74HC148DWRG4

Overview

The SN74HC148DWRG4 is an 8-line to 3-line priority encoder manufactured by Texas Instruments. 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 a typical propagation delay of 16ns, with maximum values up to 45ns depending on voltage. It provides ±4mA output drive at 5V and consumes a maximum supply current of 80μA. Packaged in a 16-pin SOIC format.

Feature Summary

• Encodes eight active-low data inputs into three active-low binary outputs while prioritizing the highest-order input.
• Includes dedicated enable input (EI) and enable output (EO) pins to facilitate cascading multiple stages for expanded encoding without external logic.
• Outputs are capable of driving up to ten LSTTL loads directly.

Applications

• N-bit encoding systems
• Code converters and generators

Procurement Notes

Verify the specific ordering suffix against the manufacturer's official documentation to confirm package type, lead finish, and environmental compliance status. Ensure the component matches the required thermal resistance and moisture sensitivity level specifications for your assembly process. Cross-reference the datasheet revision history to confirm the accuracy of electrical characteristics before finalizing procurement.

Selection Notes

Select this component when an 8-input priority encoding function is required within standard CMOS logic families. It is suitable for designs needing direct interfacing with LSTTL loads due to its drive capability. Consider the wide voltage range and low power consumption if battery-operated or variable supply environments are involved. Verify that the SOIC-16 package dimensions fit the available PCB real estate constraints.

Part Context

This part belongs to the SNx4HC148 family of priority encoders produced by Texas Instruments. It is a catalog version of the military-grade SN54HC148. The 'DWR' designation indicates a surface-mount SOIC package with tape-and-reel packaging. It is part of the broader 74HC series of high-speed CMOS logic devices designed for general-purpose digital applications.

Replacement Considerations

SN74HC148DR

FAQ

How does the SN74HC148DWRG4 handle multiple simultaneous active inputs?

It functions as a priority encoder, meaning it only encodes the highest-order active input line into the binary output, ignoring lower-priority active inputs.

What is the purpose of the EO pin?

The Enable Output (EO) pin signals when all inputs are inactive (high). It is primarily used to cascade multiple encoder stages to expand the number of addressable lines.