Preface; Product Description - Tektronix BERTScope Quick Start User Manual

Preface

This document supports the following Tektronix BERTScope Clock Recovery instruments:
CR125A with a maximum bit rate of 12.5 Gb/s
CR175A with a maximum bit rate of 17.5 Gb/s
CR286A with a maximum bit rate of 28.6 Gb/s
NOTE. Faster instruments have higher specifications. Please contact your local Tektronix representative for additional
details not mentioned in this document.
The software-based graphical user interface is accessed through the Tektronix BERTScope Analyzer top level View menu,
listed as Clock Recovery Control. Detailed information on the operation of the control interface can be accessed at any time
through the Help menus available in any of the control views.
BERTScopePC Standalone Software installs the Clock Recovery instrument control interface on a user-supplied PC. The
BERTScopePC software is included on the CD-ROM shipped with the Clock Recovery instrument.
The instrument communicates with the Tektronix BERTScope Analyzer or Host PC through a USB interface. A USB
interconnect cable is provided with the product.

Product description

The Tektronix BERTScope CR125A, CR175A, and CR286A are fully flexible clock recovery instruments designed to make
compliance testing of today's communication designs easy and accurate. With jitter being such a complex and contentious
parameter, the Tektronix Clock Recovery instrument is intended to make compliance testing simple, repeatable and accurate.
Many communication standards now specify that jitter testing must be carried out using a reference clock that has been
derived from the data signal using clock recovery with well defined loop bandwidth characteristics. Typically these
characteristics are specified in terms of the -3 dB bandwidth of the recovery loop, the rate of roll-off of the frequency
response, and the degree of response peaking allowable. These effects will greatly dictate the amount of jitter that will be
present on the reference clock, and therefore the amount of jitter ultimately measured by test instrumentation.
The Clock Recovery instrument has been designed from the ground up to provide flexibility and accuracy in compliance
measurements. For easy verification of compliance, the correct characteristics are automatically set when a given standard is
selected from a pull-down menu. However, for users wanting to explore the limits of their designs, full control of parameters
is also easily available. A good example of this is for systems where restricting the buildup of jitter is critical. Clock recovery
plays a crucial role in this, and the ability to emulate a clock recovery source with excessive peaking is a great way of
understanding the system sensitivity to jitter gain.
The Tektronix BERTScope Clock Recovery instrument is the perfect companion to the Tektronix BERTScope Bit Error Rate
Analyzer, sharing a common user interface. A single USB connection and high quality microwave coax cables connect
the two units.
CR125A, CR175A, CR286A Quick Start User Manual
Preface
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