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Jitter Spectrum and DCD Measurements

The new BERTScope™ CRJ Variable Clock Recovery Jitter Analyzer is based on our BERTScope CR, the highest performance instrumentation-grade adjustable clock recovery product available today. The CRJ retains all of the functionality of the current BERTScope CR, with additional Jitter Analysis capabilities:

• Jitter Spectrum measurements

The jitter spectrum display lets you quickly validate device compliance to serial data standards, such as PCIe 2.0, which specify a total jitter value over a band-limited range of frequency. These measurements are also very useful in isolating the source of excessive jitter in a system.

Jitter Spectrum is a unique tool, in the respect that it is extracted from the signal in the clock recovery circuit. While some sampling oscilloscopes can perform jitter spectrum measurements on repetitive signals, they can not measure jitter at frequencies below the band-pass frequency of the clock recovery loop, as these components are tracked and removed during the sampling process.

• Duty Cycle Dependent measurements

The BERTScope CRJ also directly measures Duty Cycle Dependent Jitter (DCD). The result appears in the BERTScope CRJ Display with a table of values and a graphical Level Histogram.

DCD Jitter is a required measurement in some serial data standard compliance tests. It is a useful tool in system design, for identifying jitter sources.

The BERTScope CRJ can combine with a BERTScope Signal Integrity Analyzer to directly measure jitter components from the serial input data while simultaneously generating a recovered clock. A Jitter Spectrum View in the analyzer's user interface measures spectral analysis of jitter components, along with a direct measure of duty cycle dependent jitter. Results are displayed as a plot of jitter magnitude vs. frequency. The Y-axis of the graph is scaled in %UI or time (ps). The X-axis measures frequency, with a range of 200 Hz to 90 MHz and 100 Hz resolution.

In addition, the BERTScope CRJ operates stand-alone, providing the same unmatched performance with sampling oscilloscopes and other bit error rate test instruments.

• Full BERTScope CR functionality; including compliant clock recovery from 150 Mb/s to 12.5 Gb/s, adjustable, self-measuring loop BW and peaking, plus powerful jitter measurement capability
• Direct spectral analysis of jitter components
• ‘Spectrum analyzer’ display with cursor measurements of jitter and frequency
• User-settable frequency gated measurements for band-limited
  integrated jitter
  • Preset band limits for PCIe 2.0 jitter spectrum

• Direct measure of Duty Cycle Dependent (DCD) jitter
• Passive ‘Pass through’ signal path — neither timing nor amplitude on input signal are regenerate
• Stand-alone software available for control through a PC.
• Combine with a BERTScope Signal Integrity Analyzer to use the new Jitter Spectrum View included in the analyzer's user interface.

Ordering Information
Product Code		Description
CRJ12500A		BERTScope CRJ Variable Clock Recovery Instrument with Jitter Analysis

Extended warranty and product upgrade options are available. Contact your sales representative for more information.