Obsolete MEMS oscillator — what that means for procurement
The DSC8121CM5: Availability is lot-specific and confirmed at RFQ time; expect to work with a distributor that can verify traceability and authenticity before committing the line.
MEMS resonator and programmable blank — the key spec story
It ships as a Blank (User Must Program) device — the frequency is not factory-set. You program it to any frequency in the 10 MHz to 170 MHz range using Microchip's programming tooling. That makes it a single SKU that covers a wide frequency spread, but it also means you cannot pull one from inventory and drop it onto a board without programming first.
Temperature grade and supply flexibility
That 125°C ceiling is the junction temperature, not just ambient — in a sealed enclosure with self-heating, the headroom matters. The ±10ppm frequency stability holds across that entire band, which is tighter than many industrial-grade oscillators manage over -40 to 85°C.
The 6-pad footprint is standard for this class of MEMS oscillator — no exposed thermal pad, so the layout is straightforward: decouple the supply pin with a 100nF ceramic close to the package and route the output trace with controlled impedance if the clock edge drives a long trace. Surface-mount only — no through-hole variant. The 0.90mm profile fits well under shielding cans or in tight mezzanine stacks where board-to-board clearance is limited.