Clock source for precision timing chains
The Renesas 8T49N004A-000NLGI is a single-circuit PLL clock generator from the FemtoClock® NG family. It accepts a crystal input and produces four LVPECL outputs at up to 200 MHz, with a 1:4 fanout ratio. The PLL includes a bypass mode for direct clock pass-through when synthesised jitter is not needed. It operates from a 2.375 V to 3.465 V supply and is rated over the -40°C to 85°C industrial temperature range, making it suitable for outdoor telecom basestations, industrial Ethernet switches, and test equipment that require low-jitter reference clocks.
PLL with bypass — when to use it
The PLL block is listed as Yes with Bypass. In normal operation the internal VCO locks to the crystal reference and generates a clean LVPECL clock at the programmed frequency. Bypass mode routes the input directly to the output, bypassing the PLL loop — useful during system bring-up, for test clocks, or when the output must track the input frequency without multiplication. The bypass is a hardware mux, not a software-controlled path, so it responds immediately without configuration latency.
Operates from -40°C to 85°C and a 2.375 V to 3.465 V supply. The 32-VFQFN exposed pad package (5x5 mm) provides a low-inductance thermal path.