Electronic Design

Clock Buffers Support 5-Gbit/s Serial Connectivity

The Gen2 high-performance, zero-delay clock buffers from Pericom Semiconductor provide reference clocks for PCI Express (PCIe) Gen2 serial connectivity at 5 Gbits/s. They also meet the reference-clock requirements of fully buffered dual-inline memory modules (FBDIMM) for workstation and server applications.

The family supports Intel Xeon Dual-Core processor workstation and server applications with as few as four or as many as 19 separate PCIe outputs provided by a single IC. According to the company, the buffers also surpass stringent PCIe Gen2 reference clock-jitter requirements, validated by independent testing at a Tier 1 CPU chip-set vendor lab.

Designers can combine the Gen2 clock buffers with a Pericom server motherboard clock-generator IC and a Pericom-Saronix 49SLMB high-stability crystal reference for a complete PCIe timing tree solution for Intel Dual-Core Xeon server applications. The company also offers timing products to support SAS, SARA, Gigabit Ethernet, and 10-Gigabit Ethernet protocols used with server platforms.

All of the models in the Gen2 family are available now in production quantities. Pricing ranges in 5000-unit quantities from $1.35 each for the PI6C20400S to $4.50 each for the PI6C21900 and PI6C21900S.

Pericom Semiconductor Corp.

See Associated Figure

Thanks to their AT cut crystal design, the devices in MMD Components' MOFL series provide oven-controlled crystal oscillator (OXCO) performance for the cost of a temperature-compensated crystal oscillator (TCXO). These OXCOs offer ±0.1-ppm stability from –20°C to 70°C. They also are evacuated for ultimate frequency stability over the entire operating range. Units come in industry-standard 14-pin dual-inline packages (DIPs) or in gull-wing surface-mount versions. Additionally, they provide fast warmup and use little power, consuming 200 mA during startup and less than 75 mA in steady-state operation at 25°C for a 12-V dc unit. Designers can specify operating voltages of 3.3 and 5 V as well as frequency ranges from 1 to 100 MHz. Contact the company for pricing and availability. See www.mmdcomp.com for more.

With the QiK Chip series of high-performance oscillators and voltage-controlled crystal oscillators (VCXOs) from MtronPTI, designers can allow up to four independent frequencies to be output from a single device. Their simple logic arrangement lets designers switch the oscillator output to any of the predetermined two, three, or four frequencies. Also, these devices provide better than 1-ps jitter performance and frequency precision as tight as ±20 ppm. Measuring 5 by 7 mm, the QiK Chips are available in CMOS, LVPECL, LVDS, and CML in frequencies ranging from 10 MHz to 1.4 GHz. First-article units and production volumes are available with a lead time of one to two weeks. Contact the company for pricing. For details, go to www.mtronpti.com

The oscillators in Statek's CXOMHG family can withstand shock levels up to 10,000 g. Housed in a 6.5- by 5.0-mm package, they range in frequency from 300 kHz to 120 MHz and voltage from 0.9 to 5.0 V. The oscillators in the company's CXOMHT family operate up to 200°C. They come in a 6.5- by 5.0-mm package with a 32.768-kHz frequency at 3.3 V. Statek also is developing additional quartz crystals and oscillators that can operate up to 200°C. Contact the company for pricing. See www.statek.com for details.

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