74LS AND-OR-INVERT logic in a 14-SOIC footprint
The SN74LS51NSR is a dual AND-OR-INVERT gate from the 74LS low-power Schottky family, packing two independent logic circuits in a single 14-SOIC package. Each gate implements the AND-OR-INVERT function — the first stage ANDs grouped inputs, then ORs the results, and inverts the final output — giving you a compact way to collapse multiple product-of-sums expressions into one device. Total input count is 10, split as 3, 3, 2, and 2 across the two gates, which maps directly to common combinatorial logic like address decoding or data-path gating.
Output high current is 400 µA and output low is 8 mA: the high-side sourcing is intentionally weak to limit noise on the bus, while the low-side sinking is strong enough to drive one or two standard TTL loads or a handful of 74LS inputs without external buffers. No Schmitt trigger on the inputs, so the switching threshold follows the standard 74LS V_IH/V_IL levels — clean edges on the input signal matter more here than with a Schmitt-triggered gate.
Surface-mount package and tape-and-reel handling
Available in Tape & Reel (TR) and Cut Tape (CT) options, which means it can feed into automated pick-and-place lines directly from the reel or be sampled in smaller cut lengths for prototype builds. Surface-mount mounting type keeps the board assembly in the reflow oven — no through-hole step, which simplifies the BOM assembly process for a mixed-technology board.
Active lifecycle and compliance documentation
RoHS3 compliant, so it meets the latest EU restriction on hazardous substances — no lead, mercury, cadmium, or the other restricted materials in the package or solder terminations.