High-performance synthesisers for programmable fibre optic modules

Mouser now stocks the FemtoClock2 high-performance clock-frequency synthesisers from Renesas Electronics. Offering jitter as low as 64fs RMS maximum, the synthesisers are intended to be placed adjacent to a switch, ASIC, FPGA, or PHY that needs several reference clocks with less than 100fs maximum jitter performance. Furthermore, the high-performance devices can be employed as an adjustable OTN clock reference for OTU3/OTU4 mappers and as a reference clock for programmable fibre optic modules.

The synthesisers comprise the RC22504A synthesiser and RC32504A jitter attenuator and synthesiser. The devices can also serve as a DCO for frequency margining or OTN clock applications. The devices’ PLL core consists of fractional-feedback analog PLL (optionally steered by a digital PLL in the RC32504A device) and runs from a crystal with frequencies between 25MHz to 80MHz.

The synthesisers offer four differential or eight LVCMOS outputs, supporting any frequency from 10MHz to 1GHz (180MHz for LVCMOS). These versatile synthesisers can configure themselves automatically after reset, utilising an internal customer-definable one-time programmable memory with up to four different configurations.

The synthesisers are supported by the RC22504A evaluation kit. Engineers can develop configurations using Renesas RICBox software and then upload to the evaluation board employing a USB connection. The evaluation kit offers the company’s low-noise power supply regulators and its low-noise fan-out buffer.