Texas Instruments

SN74LS26N

SN74LS26N Description

The SN74LS26N from Texas Instruments is a quad 2-input NAND gate IC belonging to the 74LS series of low-power Schottky logic devices. Housed in a 14-pin DIP package, it integrates four independent NAND gates, each featuring open-collector outputs for flexible interfacing with higher-voltage circuits or driving external loads. Designed for 4.75V to 5.25V operation, it delivers a maximum propagation delay of 32ns at 5V with a 15pF load, ensuring reliable performance in medium-speed digital systems. With TTL-compatible input thresholds (0.8V low, 2V high) and ROHS3 compliance, it suits both legacy and modern designs.

SN74LS26N Features

• Open-Collector Outputs: Enable wired-AND configurations and direct drive of relays/LEDs (up to sink current limits).
• Low-Power Schottky (LS) Technology: Balances speed (32ns delay) and power efficiency for 5V systems.
• Wide Operating Voltage Range: 4.75V–5.25V, compatible with standard TTL supplies.
• High Noise Immunity: TTL logic levels ensure robustness in noisy environments.
• Through-Hole (DIP) Packaging: Simplifies prototyping and breadboarding.
• Quad Gate Integration: Saves board space versus discrete gates.

SN74LS26N Applications

• Logic Level Shifting: Open-collector outputs interface 5V logic with higher-voltage circuits (e.g., 12V/24V industrial systems).
• Industrial Control Systems: Drive relays, solenoids, or indicators directly.
• Wired-AND Bus Interfaces: Implement shared bus architectures in multi-master systems.
• Legacy Equipment Repair: Drop-in replacement for older 74LS26/7406 designs.
• Educational Kits: DIP package aids in teaching digital logic fundamentals.

Conclusion of SN74LS26N

The SN74LS26N excels in 5V digital systems requiring open-collector flexibility, combining speed, reliability, and integration. Its open-drain outputs and TTL compatibility make it ideal for level shifting, industrial controls, and bus interfaces, while the DIP package ensures ease of use. A cost-effective solution for both new designs and legacy upgrades, it remains a staple in the 74LS family for engineers prioritizing versatility and proven performance.