Tektronix DSA8200 Series, Service Manual

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Theory of Operation
DSA8200 Digital Serial Analyzer and Modules Service Manual
2- 3
The principal POWER switch, located on the rear panel, controls all power to the
instrument including the Low Voltage Power Supply. The ON/STBY switch,
located on the front panel, also controls all of the power to the instrument except
for part of the circuitry in the Low Voltage Power Supply.
The power supply sends a power fail (~PF) warning to the processor system if
the power is going down.
The fan assembly provides forced air cooling for the instrument. The fans are
controlled by the PPC processor.
Electrical Sampling Modules Overview
The electrical sampling modules (non-TDR capable) are one- and two-channel
sampling modules. Their basic features are listed in the following table. (The
TDR capable sampling modules are describe later.)
Table 2- 1: Electrical sampling module features
Feature 80E01 80E02 80E03 80E06 80E07 80E09
Number of independent channels 1 2 2 1 2 2
Bandwidth 50 GHz 12.5 GHz 20 GHz 70 GHz 30 GHz 60 GHz
Selectable bandwidths N.A. N.A. N.A. N.A. 20 GHz,
30 GHz
40 GHz,
30 GHz,
60 GHz
Signal connectors 2.4 mm
female
3.5 mm
female
3.5 mm
female
1.85 mm (V)
female
2.92 mm (K)
female
1.85 mm (V)
female
Remote sampler N.A. N.A. N.A. N.A. 2 meter cable 2 meter cable
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).
Fans
80E01, 80E02, 80E03,
80E06, 80E07, and 80E09
Sampling Modules