SN74LS348DR

Overview

The SN74LS348DR is an 8-line to 3-line priority encoder manufactured by Texas Instruments. It belongs to the SN74LS series of logic integrated circuits and features three-state outputs for bus-driven applications. The device operates within a standard voltage range of 4.75 V to 5.25 V and is designed for commercial temperature environments ranging from 0°C to +70°C. Packaged in a 16-pin SOIC surface-mount format, it provides efficient encoding of eight input lines into binary-coded outputs.

Feature Summary

• Encodes eight distinct input lines into a corresponding 3-bit binary code representation
• Features three-state outputs allowing direct connection to system buses without external buffers
• Implements priority logic where higher-order inputs take precedence over lower-order ones during simultaneous activation

Applications

• Interrupt controller systems requiring prioritized signal handling
• Keyboard matrix scanning interfaces for data entry devices
• Address decoding circuits in microprocessor-based architectures

Procurement Notes

Verify that the specific orderable part number matches the required package style and tape-and-reel quantity specifications. Confirm compliance with current RoHS directives and environmental regulations applicable to your region before finalizing procurement orders. Ensure compatibility with existing board layout constraints regarding the SOIC-16 footprint dimensions.

Selection Notes

Select this component when designing systems requiring compact priority encoding solutions with minimal pin count. Consider the LS logic family characteristics regarding power consumption versus speed trade-offs compared to faster alternatives like AS or ALS series. Evaluate the three-state output capability against the electrical loading requirements of the connected downstream circuitry.

Part Context

This component is part of the broader SN74LS logic family produced by Texas Instruments, widely utilized in digital electronics for basic logic functions. The SN74LS348 specifically addresses the need for converting multiple parallel inputs into a condensed serial-like binary format. It serves as a fundamental building block in legacy and industrial control systems where TTL-compatible logic levels are standard.

Replacement Considerations

Compatible substitutes include the SN74LS148 and SN74LS149, which offer similar 8-to-3 priority encoding functionality. Verify pinout compatibility and electrical specifications such as propagation delay and supply current before implementing any cross-reference substitution in existing designs.