SN74LS156D

Overview

The SN74LS156D is a quad 2-line-to-4-line decoder/driver manufactured by Texas Instruments. It operates within a supply voltage range of 4.75 V to 5.25 V and features open-collector outputs with inverted logic. The device is housed in a 16-pin SOIC-Narrow package designed for surface-mount installation. It supports a commercial operating temperature range from 0°C to +70°C and belongs to the LS (Low-power Schottky) logic series.

Feature Summary

• Contains four independent 2-line-to-4-line decoders
• Provides active-low decoded outputs via open-collector configuration
• Includes dedicated low-active enable inputs for each decoder section

Applications

• Address decoding for memory systems
• Control signal generation in digital circuits
• I/O port expansion in microcontroller interfaces

Procurement Notes

Verify the specific manufacturer datasheet revision to confirm pinout compatibility and electrical characteristics against your design requirements. Ensure that the open-collector output nature is accounted for in your circuit design, as external pull-up resistors are required for proper logic high levels. Confirm the SOIC-16 package dimensions match your PCB footprint constraints.

Selection Notes

Select this component when a quad decoder with open-collector outputs is required for Low-power Schottky logic applications. It is suitable for designs needing multiple address decoding functions within a single integrated circuit. Consider the 5V TTL-compatible input thresholds and the necessity for external pull-up networks on the output lines during system architecture planning.

Part Context

This part belongs to the standard 74LS logic family, known for balanced speed and power consumption. The SN74LS156 specifically addresses the need for multiple decoding channels in compact surface-mount packages. It serves as a fundamental building block for digital control logic where signal distribution and address selection are critical.

Replacement Considerations

Compatible substitutes include the SN74LS156N (DIP package) or other manufacturers' equivalents such as the MC74LS156. Verify that replacement parts maintain the same open-collector output structure and logic functionality.