Renesas FemtoClock™, FemtoClock Next Generation (NG), FemtoClock 2, FemtoClock 3, and FemtoClock 3 Wireless devices are advanced, high-performance clock-frequency synthesizers. Employing a simple, low-cost, fundamental-mode quartz crystal as the low-frequency reference these devices synthesize high-quality, low-jitter clock signals with less than 120fs of RMS phase noise, up to 1.3GHz. The RC3 series also offers a jitter attenuation mode where it can take a noisy reference in and still provide 25fs jitter on its outputs.
FemtoClock devices are fully customizable, stand-alone solutions that generate reference frequencies allowing them to replace crystal and SAW oscillators in high-performance applications. This family of devices is often used to replace third overtone and high-frequency fundamental (HFF, inverted mesa) crystal oscillators or expensive surface acoustic wave (SAW) oscillators. They are more reliable, cost less, and are more readily available with shorter lead times.
Unlike fixed frequency oscillators, FemtoClocks are a frequency-synthesis technology (clock synthesizer) capable of multiple clock frequencies and more flexibility in any application. Because FemtoClocks are silicon IC-based clock devices, additional clock tree functions unavailable in a single function fixed-frequency oscillator can be integrated into a single device. The Renesas FemtoClock family delivers a wide range of device packages and capabilities, starting with small 8-pin TSSOP devices that provide one clean, low jitter clock signal, 4mm x 4mm QFNs that provide 4 outputs, 7mm x 7mm QFNs that provide 8 outputs, and 9mm x 9mm QFNs that provide 12 outputs. Also available are devices with more integrated functions, multiple outputs, multiple frequencies, and other more complex programmable synthesis functions.
PAM4 technology is enabling a major leap in data transmission rates in both communications and data center segments. This impacts the performance requirements of the timing source in such systems. The Renesas high-performance family of FemtoClock 3 devices delivers superior jitter performance with low power in a very small form factor, enabling placement of the clock anywhere on the board at the point of use. This greatly simplifies the design by eliminating the additive jitter associated with the extensive clock routing on the board.
Beyond PAM4, Renesas FemtoClock timing solutions are ideal reference clocks for almost any jitter-sensitive application. They are designed to provide a reference clock to PHYs, switches, ASICs, network processors, broadcast audio and video applications, and medical imaging applications. The result is a simplified board design and layout, as well as improved time-to-market. Moreover, the FemtoClock family meets the low-jitter clock specification requirements of many interface standards, such as 10 Gigabit Ethernet, PCI Express®, Fibre Channel, and SONET.
About Low-jitter Clocks
Jitter can be defined as the undesired deviation from an ideal periodic timing signal. Jitter may be observed in characteristics such as the frequency, phase, or amplitude of successive pulses. High levels of jitter can result in significant undesired system behavior in high-performance applications. Renesas offers the industry's leading portfolio of low-jitter clock synthesizers and phase-locked oscillators (PLL oscillators) to meet the needs of virtually any application.
