Triple 3-input NOR gate for wide-temperature, wide-voltage logic
The Texas Instruments CD4025BM is a triple 3-input NOR gate from the 4000B series, packaged in a 14-SOIC (3.90 mm width) for surface-mount assembly. It operates across a 3V to 18V supply range and is rated over the full military temperature span of -55°C to 125°C, making it suitable for avionics, satellite, downhole instrumentation, and other high-reliability environments where commercial or industrial parts would not survive. The 4000B family is known for its wide supply tolerance and low quiescent current — here 1 µA max — which suits battery-powered or unregulated-rail designs where a separate voltage regulator would add cost and board area.
Supply voltage and input thresholds — what they mean for the BOM
The 3V to 18V supply range is a genuine differentiator versus 5V-only or 3.3V-only logic families. A design running on a 12V battery or a 24V industrial rail stepped down to 15V can use this gate directly without a local regulator. The input low threshold is 1.5V to 4V and the high threshold is 3.5V to 11V (both vary with supply), so the gate can be driven by open-collector outputs or older 5V logic without level translation. That saves two resistors per input versus a 3.3V CMOS gate.
Output drive and propagation delay
The output can source or sink 3.4 mA (both high and low), which is typical for 4000B-series gates. That is enough to drive one or two standard CMOS inputs or a low-current LED indicator, but not a relay coil or a long cable.