SN74LS148DR

Overview

The SN74LS148DR is an 8-line-to-3-line priority encoder manufactured by Texas Instruments in the LS logic series. It converts eight active-low inputs into a three-bit binary code, prioritizing higher-order inputs. The device operates on a single power supply ranging from 4.75V to 5.25V. It features active-low outputs and includes enable input/output and group signal pins for cascading capabilities. Packaged in a 16-SOIC surface-mount format, it supports operation temperatures between 0°C and 70°C with propagation delays of approximately 19ns.

Feature Summary

• Converts eight active-low data inputs into a corresponding three-bit binary code based on input priority
• Includes dedicated enable input and output pins to facilitate cascading multiple units for expanded encoding capacity
• Generates active-low outputs representing the encoded address of the highest-priority active input

Applications

• Interrupt controller systems requiring identification of the highest priority source
• Keyboard matrix scanning circuits for detecting key presses
• Data routing systems utilizing priority-based signal selection

Procurement Notes

Verify that the specific order contains the DR suffix to confirm the 16-SOIC surface-mount package variant. Ensure the design accommodates the standard TTL voltage levels and current drive requirements specified in the official datasheet. Confirm RoHS compliance status matches project environmental regulations before final procurement.

Selection Notes

Select this component when an 8-input priority encoding function is required within standard TTL logic families. The SOIC package is suitable for automated surface-mount assembly processes. Consider the LS series characteristics regarding speed and power consumption relative to system constraints compared to other logic families.

Part Context

This part belongs to the Texas Instruments 74LS series of digital logic integrated circuits. The 74LS148 specifically functions as an octal-to-binary priority encoder. It is designed for use in general-purpose digital logic applications where reliable binary encoding of multiple signals is necessary.

Replacement Considerations

SN74LS148N (PDIP package), SN74LS148D (SOIC package). Verify pinout compatibility and electrical specifications match the original design requirements.