Tektronix TLA Series, Руководство по обслуживанию

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TLA Series Digitizing Oscilloscope Modules Service Manual
3- 1
Theory of Operation
This chapter describes the electrical operation of the DSO module. The
information supports fault isolation to the module or circuit board level. It
supplements the diagnostic information found in the
Troubleshooting section that
begins on page 6--25.
The following Block Level Description describes circuit operation to the
functional block level. When reading this description, refer to Figure 9--1 and
Figure 9--2 for interconnection and block diagram illustrations, respectively.
Block Level Description
The block level description provides an overview of each functional circuit
within the DSO module. Except for the number of channels, the basic operation
is the same for each model. The TLA7D2 and TLA7E2 models have four input
channels. The TLA7D1 and TLA7E1 have two input channels.
Input signals to be measured enter the DSO module through probes or cables
connected to BNC connectors on the front panel. A probe interface detects the
attenuation factor of each probe. The probe data is routed to the Acquisition
Board (A2) where it is used to set the vertical scale.
The front-panel BNC provides a probe compensation signal. A coaxial cable
assembly routes the signals between the front panel and the circuit boards.
The Acquisition Board (A2) accepts analog input signals and converts them to
digital information. Two 100-pin ribbon cables provide interconnections with the
Processor Board (A1) for power supplies, waveform data, and control signals.
The Acquisition Board (A2) consists of the following circuits:
H
Attenuators
H
Acquisition System
H
VCO
H
Trigger
H
Intermodule Triggers
Input/Output Connectors
Acquisition Board (A2)