125 MHz HCSL clock — PCIe and serial-link reference
The DSC1124BE1-125.0000 is a 125 MHz MEMS-based XO with HCSL output — the differential current-mode logic used for PCIe Gen 1/2/3, SATA, and Ethernet reference clocks. HCSL swings 700-900 mV peak-to-peak into 50 Ω to ground, so the receiver sees a clean edge without external termination to a bias voltage. The 125 MHz frequency matches the common PCIe reference; a 25 MHz crystal multiplied up would add jitter from the PLL, but this part delivers the base frequency directly.
Supply range and enable/disable function
Runs from 2.25 V to 3.6 V — a single 3.3 V or 2.5 V rail works without an extra regulator. That matters for power-gated subsystems: the oscillator stops drawing the full 42 mA when the downstream PHY or controller is off.
6-SMD no-lead package, 5.00 mm × 3.20 mm body, 0.90 mm seated height. The 0.197" × 0.126" footprint fits the standard 5×3.2 mm oscillator land pattern — no via-in-pad needed. The MEMS die sits inside a ceramic cavity, so reflow profile follows the standard JEDEC MSL-1 moisture sensitivity; no bake required before assembly if the bag seal is intact.
Fine for networking gear, base stations in a climate-controlled shelter, test equipment, or office electronics. Not rated for -40°C cold start or 85°C engine-bay ambient; if the board sees those extremes, look at the DSC1124 extended-temp variants or a different oscillator family.