Tektronix DSA8300 Service Manual page 27

80E04, 80E08, and 80E10
TDR/Sampling Modules
DSA8300 Digital Serial Analyzer and Modules Service Manual
For the two-channel modules, a single strobe delivered from the instrument
mainframe to both acquisition channels controls the timing of the strobe assertion
to both channels. If channel-to-channel deskew is zero and the channel delays (if
equipped) are matched, the sampling coincidence between channels is very close.
Acquisition deskew function is carried out either by making separate acquisitions
over individual acquisition windows or by adjusting Channel Delay (if equipped).
For the one-channel modules, an individual strobe delivered from the instrument
mainframe to the acquisition channel controls the timing of the strobe assertion
to the channel. Acquisition deskew function is carried out by moving the strobe
timing for the channel to a unique acquisition window or by adjusting Channel
Delay (if equipped).
Most electrical channels feature a Tekprobe Level 2 probe power connector for
attachment of a real time probe. The control of this probe is a mainframe function.
All module calibration signals are derived from a 2.5 V precision voltage reference
internal to the sampling module. Settings derived from this reference are stored in
a nonvolatile EEPROM in the sampling module, although the responsibility for
the execution of these settings is with the mainframe.
The TDR/Sampling modules are low noise samplers, with each channel capable
of generating its own Time Domain Reflectometry (TDR) step. The basic features
of these modules are listed in the following table.
TDR sampling module features
Feature 80E04
Number of 2
independent
channels
2
Number of TDR
channels
Bandwidth 20 GHz
Selectable N.A.
bandwidths
Signal connectors 3.5 mm female
Remote sampler N.A.
For these modules, a single strobe delivered from the instrument mainframe to
both acquisition channels controls the timing of the strobe assertion to both
channels. If channel-to-channel deskew is zero and the channel delays (if
equipped) are matched, the sampling coincidence between channels is very close.
Acquisition deskew function is carried out by making separate acquisitions over
acquisition windows or by adjusting Channel Delay (if equipped).
Each electrical channel features a Tekprobe Level 2 probe power connector for
attachment of a real time probe. The control of this probe is a mainframe function.
Theory of Operation
80E08 80E10
2 2
2 2
30 GHz 50 GHz
20 GHz, 30 GHz 40 GHz, 30 GHz,
50 GHz
2.92 mm (K) female 1.85 mm (V) female
2 meter cable 2 meter cable
2–5