SyntheSys Research BERTSCOPE CR
Clock Recovery Unit for BERTScope

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Product Overview

SYNTHESYS RESEARCH BERTSCOPE CR (CR12500A)

The BERTScope CR’s advanced architecture measures and displays the PLL frequency  response from 100 kHz to 12 MHz; the highest loop bandwidth available for  jitter testing on the market today. The first  clock recovery instruments to allow full control of parameters including loop bandwidth, peaking/damping and rolloff. 

Design and test engineers can find and lock onto signals of undefined or unknown data rate. The engineer can recover full rate clocks, including spread spectrum clocks, for signals at data rates from 150 Mb/s to 12.5 Gb/s. The engineer has full control of key parameters for variable loop bandwidth, peaking/damping and first and second order rolloffs, optimizing jitter tracking. 

Many test standards require the use of a Golden PLL (phase lock loop.) Control of the BERTScope CR variable loop bandwidth allows for control of the jitter transferred to the recovered clock. When the loop bandwidth setting is narrow, much of the high frequency jitter is removed from the clock signal. The narrowest LBW setting is desirable when a clock with the lowest possible jitter is required. When the loop bandwidth setting is wide, jitter is transferred to the recovered clock, emulating a clock signal similar to the CDR of the receiver under test. Each standard provides an optimum LBW setting for clock recovery often called the Golden PLL.

Spread Spectrum Clocking (SSC) is an increasingly required feature of serial bus standards. When employed, it can prove difficult to track but its effect must be included in test. The CR12500A instruments are able to track SSC correctly with large frequency excursions up to 5000 ppm, making them unique amongst clock recovery test solutions. The BERTScope CR is the first clock recovery instrument to recover clocks from spread spectrum clocked signals used in Serial ATA, SAS, PCI Express and FB DIMM applications.