MEMS oscillator with dual HCSL clock outputs
The DSC400-4444Q0023KI2 is a MEMS-based XO (Standard) oscillator from Microchip's DSC400 family, generating two independent HCSL outputs at 100 MHz and 156.25 MHz. HCSL (High-Speed Current Steering Logic) is the standard clock format for PCIe reference clocks — the 100 MHz output directly serves a PCIe root complex or switch, while the 156.25 MHz output is common for 10GbE and 25GbE Ethernet PHY reference clocks.
Supply voltage and power-tree fit
The wide supply range of 2.25V to 3.6V means this oscillator can run directly from a 2.5V or 3.3V rail without an intermediate LDO — a single 3.3V supply powers the oscillator and the downstream PCIe or Ethernet ICs.
The 20-VFQFN with exposed pad (5.00 mm x 3.20 mm, 0.90 mm height) requires a thermal via array under the pad for proper heat dissipation — the exposed pad is the primary thermal path, not the package body. The 0.50 mm pitch of the QFN package demands careful fan-out; a 4-layer PCB with ground plane under the oscillator is recommended to maintain signal integrity on the HCSL outputs.
Lifecycle and sourcing status
No stock-holding claim — quoted to order.