Triple 3-input NOR gate in the 74HC family
The CD74HC27M is a triple 3-input NOR gate from Texas Instruments' 74HC series, packaged in a 14-SOIC surface-mount body. It integrates three independent NOR gates, each with three inputs, on a single IC — a compact logic building block for gating, decoding, or latch-disable circuits in mixed-voltage digital systems.
Supply range and logic thresholds
The low-level input threshold sits at 0.5 V to 1.8 V, and the high-level threshold at 1.5 V to 4.2 V — these shift with the supply rail, so the gate remains TTL-compatible at 5 V and CMOS-compatible at 3.3 V. Quiescent current maxes at 2 µA across the full supply range, making the part suitable for battery-backed or always-on logic where the gate's own draw must stay below the system sleep budget.
Output drive and timing
Each output sources and sinks 5.2 mA — enough to drive a single standard CMOS load or a low-power LED indicator directly, but not a high-fanout bus without a buffer. Propagation delay is 16 ns max at 6 V with a 50 pF load, which sets the ceiling for the data path: cascading several gates in a ripple chain adds delay that must close within the clock period.
Temperature grade and package
This covers engine-bay electronics, outdoor telecom cabinets, and cold-chain data loggers where the board sees extremes.