MEMS XO with HCSL – dual-frequency clock source
The DSC400-0404Q0020KE1T is a MEMS-based XO (Standard) from Microchip's DSC400 series, delivering two fixed output frequencies: 125 MHz on Output 1 and 100 MHz on Output 2, both in HCSL logic levels. HCSL (High-Speed Current Steering Logic) is the common clock standard for PCI Express reference clocks — this oscillator can directly drive a PCIe Gen1/2/3 PLL without external level translation. Supply voltage spans 2.25 V to 3.6 V, covering 2.5 V and 3.3 V rails with margin; the Enable/Disable function lets the system gate the outputs for power sequencing or test modes.
Frequency stability and temperature grade
The -20°C lower limit means this part is specified for indoor, office, or appliance environments; it is not rated for outdoor base stations, engine bays, or cold storage where -40°C operation is needed.
Housed in a 20-VFQFN with exposed pad (5.00 mm x 3.20 mm, 0.90 mm height), the package requires a thermal via array under the pad for proper heat transfer and mechanical stability — the exposed pad must be soldered to a ground plane.