Dual 2-input NAND gate with open-drain output — what it means on the board
The CD40107BM is a dual 2-input NAND gate from the 4000B series, packaged in an 8-SOIC. Its distinguishing feature is the open-drain output — the high-side driver is absent, so the output can only sink current to ground, not source it. That makes this part a natural fit for driving loads referenced to a higher supply rail: relay coils, LEDs with a series resistor to Vcc, or level-shifting a logic signal to a different voltage domain. The open-drain stage also allows wired-OR connections where multiple gate outputs share a common pull-up resistor. Supply range spans 3 V to 18 V. Operating temperature range is -55°C to 125°C. Quiescent current is 4 µA maximum, so the gate adds negligible draw in battery-backed or always-on circuits. Propagation delay is 100 ns at 15 V with a 50 pF load — adequate for slow control signals, panel pushbuttons, or debounced sensor inputs, but not for high-speed clock trees.
68 mA sink — sizing the load
Output sink current is 68 mA; no source current specified.
Lifecycle and compliance
The CD40107BM is listed as Active in production and ROHS3 compliant.