SN74LS42N

Overview

The SN74LS42N is a BCD-to-decimal decoder manufactured by Texas Instruments, belonging to the SN54/74LS series. It features four binary-coded decimal inputs and ten active-low outputs. The device operates within a supply voltage range of 4.75 V to 5.25 V and supports a propagation delay of 30 ns. It is housed in a 16-pin PDIP package with through-hole mounting capabilities. The component functions as a single circuit decoder suitable for standard logic applications.

Feature Summary

• Converts four-bit binary coded decimal input signals into one of ten mutually exclusive active-low output lines
• Utilizes low-power Schottky (LS) logic technology for efficient operation
• Designed for direct connection to TTL or MOS memory address decoders

Applications

• Memory address decoding in digital systems
• Control logic circuits requiring specific output activation based on binary inputs
• Display driver interfaces for decimal readouts

Procurement Notes

Verify the specific ordering suffix against the manufacturer's current datasheet to confirm package type and temperature grade. Ensure compatibility with existing PCB footprints for the 16-PDIP configuration. Confirm RoHS compliance status if required by project specifications. Cross-reference part numbers with authorized distributors to avoid counterfeit components.

Selection Notes

Select this component when a dedicated BCD-to-decimal conversion function is required within a TTL-compatible logic family. Consider the 30 ns propagation delay and 4.75 V to 5.25 V operating range against system timing and power constraints. Evaluate the 16-PDIP package suitability for through-hole assembly processes compared to surface-mount alternatives.

Part Context

This decoder is part of the extensive SN54/74LS logic family produced by Texas Instruments. It serves as a fundamental building block for digital design, specifically handling binary to decimal translation. The LS designation indicates low-power Schottky characteristics, balancing speed and power consumption relative to standard TTL counterparts.

Replacement Considerations

SN74LS42AN