SN74LS148NSR

Overview

The SN74LS148NSR is an 8-line-to-3-line priority encoder manufactured by Texas Instruments. It operates within a supply voltage range of 4.75V to 5.25V and features a propagation delay of 19ns with a maximum clock frequency of 35MHz. The device dissipates 60mW of power and supports output currents of -400µA (high) and 8mA (low). It is housed in a 16-pin SOIC package, operates between 0°C and 70°C, and complies with RoHS3 standards.

Feature Summary

• Encodes eight active-low inputs into a three-bit binary code based on priority levels.
• Provides dedicated enable input and output signals for cascading multiple units.
• Utilizes standard TTL logic family characteristics for reliable digital signal processing.

Applications

• Interrupt controller systems requiring priority handling
• Keyboard encoding circuits
• Data multiplexing applications

Procurement Notes

Verify the specific suffix 'SR' indicates tape-and-reel packaging when sourcing. Confirm RoHS3 compliance status matches current manufacturing revisions. Ensure the operating temperature range aligns with system requirements. Cross-reference datasheet revision numbers to guarantee pinout consistency. Validate that the 16-SOIC footprint matches the target PCB design constraints.

Selection Notes

Select this component for designs requiring standard TTL compatibility and moderate speed performance. Consider alternative HC or HCT series variants if lower power consumption or wider voltage ranges are necessary. Verify that the 19ns propagation delay meets the timing constraints of the target application. Ensure the 16-SOIC package size fits the available board space.

Part Context

This part belongs to the Texas Instruments 74LS logic family, known for standard TTL performance. It functions as a core building block in digital logic systems for converting multiple input lines into encoded outputs. The device is widely used in legacy and modern embedded systems requiring simple priority encoding capabilities.

Replacement Considerations

SN74LS148N: PDIP-16 through-hole equivalent. SN74LS148DR: SOIC-16 surface mount variant from the same manufacturer. SN54LS148: Military-grade version with extended temperature range.