Active single-gate AND with open-drain output
The SN74AHC1G09DCKR is a single 2-input AND gate with an open-drain output, part of TI's 74AHC logic family. The open-drain output means the high-side driver is missing — the output can only sink current, not source it, so you pull it up externally to whatever voltage the downstream logic needs, up to 5.5 V. That makes it handy for level-shifting or wired-OR buses where multiple gates share a common pull-up.
What the ratings mean for a field swap
The open-drain output is rated for 8 mA sink current — enough to drive a standard LED or a logic input on a 74HC/74LVC part, but not a relay coil or a heavy load. The propagation delay is 7.5 ns max at 5 V with a 50 pF load, so it keeps up with most control signals below 50 MHz. Quiescent current maxes out at 1 µA across the full voltage and temperature range — negligible for battery-powered gear that sleeps most of the time.
Package and board-fit: SC-70-5
Housed in a 5-pin SC-70-5 (also known as SOT-353), the part is small enough to fit in tight spots — about 2.0 mm × 1.25 mm footprint. The pinout is standard: GND, inputs A and B, output Y, and VCC.