SN74LS145N

Overview

The SN74LS145N is a BCD-to-decimal decoder/driver from the Texas Instruments LS series. It features four inputs and ten open-collector outputs, designed to decode binary-coded decimal information into one of ten active-low outputs. The device operates on a single power supply ranging from 4.75 V to 5.25 V. Key electrical parameters include a propagation delay of 50 ns, a low-level output current capability of 80 mA, and a high-level output current of -250 μA. It functions within a commercial temperature range of 0°C to 70°C and is housed in a 16-pin PDIP package.

Feature Summary

• Decodes four-bit binary-coded decimal (BCD) input signals into ten distinct active-low decimal outputs.
• Provides high sink current capability through open-collector outputs suitable for driving external loads.
• Compatible with standard TTL logic levels for seamless integration into digital systems.

Applications

• Driving decimal display indicators such as Nixie tubes or vacuum fluorescent displays.
• Controlling relay driver circuits requiring direct switching of external loads.
• Implementing sequential control logic in industrial automation equipment.

Procurement Notes

Verify the specific manufacturer source, as components bearing this part number are produced by multiple vendors including Texas Instruments and NXP. Confirm the package type matches requirements, noting that some variants may utilize different pin configurations or lead materials. Ensure compliance with environmental regulations regarding lead content if applicable to the specific production batch.

Selection Notes

Select this component when a dedicated BCD-to-decimal translation function is required with high-current sinking capabilities. It is appropriate for designs utilizing open-collector outputs to interface with higher voltage loads or distinct indicator types. Consider the propagation delay and power consumption characteristics relative to other logic families if speed or efficiency is critical.

Part Context

This device belongs to the SN74LSxx series of Low-power Schottky TTL logic devices. It serves as a specialized decoder within the broader family of digital logic components, providing specific translation functionality rather than general-purpose gating or storage. Its design supports standard digital system architectures requiring decimal decoding.

Replacement Considerations

Direct functional equivalents include the SN74LS445 and SN54145. Verify pin compatibility and electrical specifications before substitution, as variations in output drive strength or package style may exist between manufacturers.