Theory of Operation
3–4
CSA8000 & TDS8000 Instruments and Sampling Modules
The 80E04 TDR/Sampling module is a two-channel, low noise, 17.5 ps rise time
sampler. Each channel is also capable of generating its own Time Domain
Reflectometry (TDR) step. The 80E04 sampling module risetime is 17.5 ps.
For the 80E04 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, the sampling coincidence between
channels is very close. Acquisition deskew function is carried out by making
separate acquisitions over acquisition windows.
Each electrical channel features a Tekpobe 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 non-volatile EEPROM in the sampling module, although the
responsibility for the execution of these settings is with the mainframe.
When used in the acquisition mode (that is, with the TDR step generator turned
off) each channel functions as a normal sampling input. Both channels are
strobed simultaneously from a single strobe generator contained within the
sampling module, so time coincidence between the two channels is stable.
In the TDR mode, a fast rise time step is generated internally for each channel
and applied to the input signal path for that channel. The acquisition portion of
the TDR/sampling module remains functional for monitoring the primary step
and its reflected components. The sampling module provides two self- contained
TDR channels. The polarity of the output step can be selected independently for
each channel. This allows differential or common mode testing of two coupled
lines as well as independent testing of isolated lines.
For major functional circuit blocks refer to (Figure 9–4).
80E04 Electrical
TDR/Sampling Module
Summary of Contents for CSA8000 Series
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Page 18: ...Service Safety Summary xiv CSA8000 TDS8000 Instruments and Sampling Modules ...
Page 22: ...Preface xviii CSA8000 TDS8000 Instruments and Sampling Modules ...
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Page 59: ...80C00 Modules Specifications 1 36 CSA8000 TDS8000 Instruments and Sampling Modules back ...
Page 63: ...80A01 Module Specifications 1 40 CSA8000 TDS8000 Instruments and Sampling Modules ...
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Page 74: ...Installation 2 10 CSA8000 TDS8000 Instruments and Sampling Modules ...
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Page 103: ...Theory of Operation 3 10 CSA8000 TDS8000 Instruments and Sampling Modules ...
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Page 106: ...Performance Verification Procedures 4 2 CSA8000 TDS8000 Instruments and Sampling Modules ...
Page 122: ...Brief Procedures 4 18 CSA8000 TDS8000 Instruments and Sampling Modules ...
Page 126: ...Performance Tests 4 22 CSA8000 TDS8000 Instruments and Sampling Modules ...
Page 218: ...80A01 Trigger Preamplifier Module 4 114 CSA8000 TDS8000 Instruments and Sampling Modules ...
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Page 231: ...Maintenance 6 6 CSA8000 TDS8000 Instruments and Sampling Modules ...
Page 291: ...Removal and Installation Procedures 6 66 CSA8000 TDS8000 Instruments and Sampling Modules ...
Page 307: ...Repackaging Instructions 6 82 CSA8000 TDS8000 Instruments and Sampling Modules ...
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Page 315: ...Electrical Parts List 8 2 CSA8000 TDS8000 Instruments and Sampling Modules ...
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