Tektronix DSA8200 Series, Руководство по обслуживанию

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Theory of Operation
2- 14
DSA8200 Digital Serial Analyzer and Modules Service Manual
The high bandwidth circuit recovers clock and data from input data in the
2.7 Gb/s to 12.6 Gb/s range. The recovered clock to the front panel and internal
trigger signals are always clock/16.
With option 10G, the 10G recovered clock is also routed to the front panel.
There is one front panel indicator LED -- Clock Recovery Enable. It indicates the
clock recovery circuitry is on and programmed to the requested bit rate.
For major functional circuit blocks refer to Figure 5--5 on page 5--6.
80A06 PatternSync Trigger Module
The 80A06 PatternSync Trigger Module is designed to provide a frame trigger
for the DSA8200.
The frame trigger is derived by counting a programmed amount of user supplied
clock cycles and generating a pulse at the completion of the count. This pulse is
then routed externally to the main instrument’s external trigger direct input.
An additional buffered copy of the input clock is output to the front panel for
connection to additional equipment such as an 82A04 Phase Reference Module.
The 80A06 consumes a small slot or may be operated on a SlotSaver cable
connected to the main instrument’s probe power connector.
Pattern triggering works for clocks in the range of 150 MHz to 12.75 GHz.
For major functional circuit blocks refer to Figure 5--6 on page 5--7.
82A04 Phase Reference Module
The 82A04 Phase Reference Module is designed to decrease horizontal position
uncertainty with data signals, when a reference clock signal synchronized to the
data signal, is available. It consumes a small slot, and displaces operation of both
channels in that slot.
The Phase Correction modes available are free run, where the module provides
unit circle location information for the phase of the data sample, and triggered,
where the module, in conjunction with the trigger signal, provides both base
positioning, and refined positioning, for the data sample.
The input is precision 1.85 mm. Phase correction works over the range of
2.5 GHz -- 25 GHz (82A04), or 2.5 GHz -- 60 GHz (82A04--60G). The LED
indicates the module is being utilized for phase correction.