Theory of operation
The recovered clock is routed to the rear connector of the module and sent to the
Optical Front End board in the mainframe. The Optical Front End board has a
switch that selects which modules clock is applied to the trigger. The control
signal for that switch comes from the optical module.
The main board of the optical module provides power and control bits to the clock
recovery board. A small fraction of the input signal is split off internally and
applied to the clock recovery components. The type of splitter for each module is
shown in the following table.
Internal optical/electrical split for clock recovery
Module
Optical Split
Electrical Split
80C01
•
80C02
•
80C03
•
80C04
•
80C07/B
•
80C08/B/C/D
•
80C09
•
80C10/B/C
1
80C11/B
•
80C12/B
1
1
No clock recovery option available.
Some optical modules (such as the 80C10C and 80C15) have an optional clock
recovery trigger pickoff (CRTP) function that provides a second, high-sensitivity
optical input to drive electrical differential DATA and DATA outputs. These
differential data signals are connected to the BERTScope CR286A Clock
Recovery instrument for clock recovery or error detection
80A01 trigger prescale preampli
fi
er module
The 80A01 module is designed to increase the sensitivity of the prescale trigger
input of the DSA8300 to
≤
200 mV
p-p
.
The major function block of the module is a high sensitivity, high gain RF
ampli
fi
er. The input and output to this ampli
fi
er are routed to two identical SMA,
female connectors, labeled Input and Output at the module front panel.
The module receives power from the main instrument through a single connector
at the rear of the module. The power LED indicates the module is receiving power
through the interface connector.
DSA8300 Digital Serial Analyzer and Modules Service Manual
9
