HCSL output for PCIe and high-speed serial clocks
The DSC1104CE2-027.0000T: This oscillator delivers a 27 MHz HCSL (High-Speed Current Steering Logic) output, the standard for PCIe reference clocks and many high-speed serial interfaces. Unlike LVDS or LVPECL, HCSL swings from ground to about 0.7V and requires a 50-ohm termination to ground at the receiver — a detail that matters when laying out the clock trace.
MEMS resonator vs quartz: what it changes on the BOM
The trade-off is that MEMS parts have slightly higher phase noise at close-in offsets, but for a 27 MHz HCSL clock feeding a PCIe reference, the jitter budget is usually met without issue.
When enabled, the oscillator draws 42 mA max at 27 MHz. For a battery-powered board that sleeps between operations, this standby current is low enough to leave the oscillator powered continuously — no need for a load switch on the Vdd rail.
Runs from 2.25V to 3.6V, covering both 2.5V and 3.3V logic rails without a separate regulator. Not rated for automotive or extended industrial ambient.
6-SMD, no-lead package, 3.20 mm x 2.50 mm body, 0.90 mm seated height. The 0.126" x 0.098" footprint is compatible with standard 3.2 x 2.5 mm oscillator pads. No thermal pad — the part dissipates under 150 mW at 3.6V, so a standard FR-4 copper pour under the package is sufficient.