200 MHz fanout buffer for clock distribution
The Renesas 621SCMGI is a single-circuit fanout buffer that takes one clock input and delivers four LVCMOS outputs, rated up to 200 MHz. It is not a differential buffer — both input and output are single-ended (No/No for differential I/O), so it fits standard CMOS clock trees where you need to split a reference clock to multiple loads without adding a PLL or divider. The 1:4 ratio is useful for fanning a master oscillator to several peripherals — MCU, Ethernet PHY, FPGA bank — while keeping the drive strength clean.
The supply range spans 1.71 V to 3.465 V, covering 1.8 V, 2.5 V, and 3.3 V logic rails without needing a separate regulator. The 105°C ceiling gives thermal margin for designs with limited airflow or proximity to hot power stages.
Housed in an 8-UFDFN package (supplier device package 8-VFQFN, 2x2 mm), this is a small surface-mount device suited for dense PCB layouts. The 2x2 mm footprint and 0.5 mm pitch are typical for a low-pin-count clock buffer; the exposed pad (if present) should be stitched to ground with a via array under the package for thermal relief.
For dual-sourcing resilience, the Renesas 5PB1104CMGK/W is a functional peer with the same LVCMOS output type, 1:4 ratio, and 200 MHz ceiling — though the package variant differs (Tape & Reel vs Strip).