The Molex 5031821852 is a surface-mount, right-angle microSD™ card connector from the 503182 series, integrating both the connector body and a card ejector into a single 10-position (8 + 2) package. The extra two positions are a dedicated card detect switch — a feature that lets the host controller sense when a card is fully seated, without needing a separate mechanical switch elsewhere on the board. It accepts standard microSD cards, with a push-in/push-out insertion and removal method, and sits just 1.45 mm above the PCB.
The Card Detect Switch — What It Does for the Design
The switch feature is the detail that separates this part from a plain microSD connector. When the card is pushed fully home, the switch contacts close, signaling to the processor that the card is present and ready. That saves a GPIO pin and a debounce circuit you'd otherwise need to add. For a field-service perspective: if a device intermittently loses the card, the first thing to check is whether the switch is making contact — a bent switch terminal on the SMT pad is a common failure point after rework. The gold contact finish on the signal pins helps here too: it handles the repeated insertion cycles of field use better than tin would, so the card detect signal stays reliable over thousands of mates.
Mounting and Board Layout Notes
Surface mount, right-angle orientation means the card inserts parallel to the PCB, not perpendicular — the card sits flat against the board, which keeps the overall z-height down to the 1.45 mm the connector itself occupies. The right-angle body also puts the card slot at the board edge, which is typical for an enclosure's SD card cutout. The Tape & Reel packaging is what you expect for an SMT part destined for a pick-and-place line; the Cut Tape option is there for prototyping or low-volume builds where you don't want to commit to a full reel. The base product number 503182 covers the series, so if you're searching for a different position count or height variant, that's the family root to look under.