Silicon Laboratories expands clock generator range

The Si535x devices are made-to-order, eight-output CMOS clock generators capable of synthesising four unique, non-integer related frequencies from 1-200MHz.

The generators provide guaranteed 0ppm frequency synthesis error for any combination of frequencies, enabling the replacement of multiple clock ICs and crystal oscillators with a single device.

Through a flexible web configuration utility called Clockbuilder, factory-customised, pin-controlled Si5355 devices are available in less than two weeks, enabling faster time to market while reducing the bill of materials in cost-sensitive networking, data communication, telecom access, computing and general purpose applications.

Modern hardware designs require a diverse combination of non-integer related reference frequencies for processors, memory, and peripheral interfaces (e.g, Ethernet, PCI Express, USB, wireless LAN, IEEE1394).

The Si5355 leverages a single PLL architecture and Silicon Laboratories' MultiSynth fractional divider technology to provide greater frequency flexibility and lower jitter than 3 or 4 PLL clock generators.

It can replace multiple clock ICs and crystal oscillators with a single IC and has consistently low jitter (50ps pk-pk period jitter), regardless of frequency configuration.

The Si5355 can generate any combination of output frequencies from a standard, low-cost 25 or 27MHz crystal.

If the device frequency plan changes, the same crystal can be reused, eliminating the higher cost associated with custom frequency crystals required by some traditional solutions.

Alternatively, the Si5355 supports a 5-200MHz reference clock input, enabling the device to be used in synchronous applications.

Silicon Labs' ClockBuilder web-based utility provides turnkey, application-specific clocks, eliminating the need for field programming hardware and software.

Since the Si5355 does not require metal mask changes to customise clock frequencies like traditional clocks ICs, Silicon Labs can reduce the lead time associated with custom clocks from six weeks to less than two weeks.

The Si535x family includes the Si5356, an I2C-programmable Any-Rate 1-200MHz spread spectrum clock generator.

Spread spectrum is available on any clock output with any frequency and any spread amount.

If system-level electro-magnetic interference (EMI) testing confirms that spread spectrum is required by an application, spread spectrum can simply be enabled by pin selection without the need for component or firmware changes, further simplifying qualification testing and shortening the overall development cycle.

The Si5355/56 products are available in a 4 x 4mm 24-QFN package with samples and production quantities available now.