DM74LS156N

Overview

The DM74LS156N is a dual 2-line to 4-line decoder/demultiplexer featuring open-collector outputs. It operates within a supply voltage range of 4.75V to 5.25V and supports an operating temperature of 0°C to +70°C. Propagation delays vary from 18ns to 53ns depending on input/output configuration and load capacitance. The device utilizes common binary-address inputs (A, B) and individual strobes (G1, G2) for section control.

Feature Summary

• Dual independent sections with common address inputs
• Open-collector output structure
• Individual strobe inputs for selective activation
• Input clamping diodes for transmission-line protection

Applications

• Dual 2-to-4-line decoding
• Dual 1-to-4-line demultiplexing
• Cascaded 3-to-8-line decoding
• Cascaded 1-to-8-line demultiplexing

Procurement Notes

Verify the manufacturer origin, as the datasheet indicates Fairchild Semiconductor. Confirm RoHS compliance status, as legacy TTL parts may not meet current environmental standards. Check for tape and reel availability by appending the 'X' suffix if required. Ensure the PDIP-16 package matches the design footprint.

Selection Notes

Select this component when open-collector outputs are required for wired-AND configurations or level shifting. Compare propagation delay specifications against system timing requirements. Consider the DM74LS155M/N if totem-pole outputs are needed instead of open-collector. Verify voltage levels match the 5V logic family constraints.

Part Context

This part belongs to the 74LS series of TTL logic devices. It provides dual decoding or demultiplexing functions in a single 16-pin DIP package. The open-collector variant allows for flexible interfacing with different load types compared to standard push-pull outputs.

Replacement Considerations

DM74LS155N offers identical functionality with totem-pole outputs instead of open-collector.