The DSC1121CE5-108.0000T is a 108 MHz MEMS-based oscillator from Microchip's DSC1121 series, delivering a CMOS output with ±10 ppm frequency stability across a 2.25V to 3.6V supply range.
The MEMS base resonator eliminates the quartz cold-start frequency overshoot and vibration sensitivity that can cause bit errors in high-speed serial links (e.g., 100BASE-T1 or CAN-FD). ±10 ppm stability over the full -20°C to 70°C range keeps the clock within the tight window required by 108 MHz Ethernet PHY reference clocks — a quartz crystal at this frequency would typically need a TCXO to match that hold. The 3.20mm x 2.50mm 6-SMD footprint is a standard ceramic package land pattern; no special layout considerations beyond the usual decoupling capacitor at the supply pin.
The base product number DSC1121 covers multiple frequency and stability variants; the CE5 suffix encodes the 108 MHz frequency and ±10 ppm stability grade, so a BOM change to a different DSC1121 variant requires only a new suffix, not a PCB spin.