What this MEMS oscillator does in the assembly
The DSC1001BI2-018.4320T is a MEMS-based XO (Standard) from Microchip's DSC1001 series, delivering a fixed 18.432 MHz CMOS clock output with ±25 ppm frequency stability across its operating range.
Operating from 1.8V to 3.3V, this single oscillator covers 1.8V, 2.5V, and 3.3V logic rails — a BOM simplification when the same clock feeds a mixed-voltage system. The 6.3 mA max supply current is the full-load draw at 18.432 MHz; in standby the oscillator sinks 15 µA.
Housed in a 4-SMD, no-lead package measuring 5.00 mm × 3.20 mm with a seated height of 0.90 mm, the footprint is compatible with standard 5.0×3.2 mm oscillator land patterns.
No direct pin-compatible second source is documented, but the DSC1001 series includes multiple frequency and stability variants sharing the same package and pinout.