Theory of Operation
3-2
AWG2021 Service Manual
This functional block is a 12-bit high-speed digital-to-analog converter. It
converts the digital data from the waveform memory into analog signals.
This analog processing block amplifies the analog signals from the DAC to the
necessary amplitude. If an offset is specified, this circuit adds that offset and
outputs the result at the output connector for that channel. This circuit also
contains a filter, an AM modulator, and other elements that modify waveform
output. Its output impedance is 50
W
.
This functional block directs operation of all internal circuits, based on front
panel control operation and commands received over the GPIB or RS-232-C
interface. This circuit includes the 68000 CPU, DRAM, EPROM, and SRAM.
Data in memory is retained by a lithium battery on the A5 Backplane board.
CAUTION.
To avoid losing waveform data files stored in NVRam, save the files to
a floppy disk before removing the A6 CPU board or A5 Backplane board. Then
restore the files from floppy disk to AWG2021 nonvolatile memory after
reinstalling the board(s).
This functional block is the General Purpose Interface Bus (GPIB) interface
driver, which controls communication with external devices over the parallel
interface. The GPIB connector is on the rear panel.
This functional block is the RS-232-C interface circuit which controls serial
communication with external devices over the RS-232-C interface. The
RS-232-C interface connector is on the rear panel.
The display control block processes the test and waveform information based on
commands from the processor. The block sends the text and waveform informa-
tion to the display monitor as video signals, with vertical and horizontal sync
control.
This display monitor takes in the video signals and displays them on a 17.8 cm
(7 in.) CRT screen. The display resolution is 480
×
640 pixels.
The front panel block includes the buttons, keys, and knobs for entering
selections. User selections from the front panel are sent to the processor. The
buttons at the bottom and side of the display are also included in this block.
Commands from the processor control an LED in the buttons.
DigitalĆtoĆAnalog
Converter (DAC) (A2,
Memory Board)
Analog Processing (A3,
Analog Board)
CPU and Memory (A6,
CPU Board)
GPIB (A6, CPU Board)
RSĆ232ĆC (A6, CPU Board)
Display Control (A6, CPU
Board)
Display Monitor
Front Panel (A12,
Keyboard)
Summary of Contents for Tektronix AWG2021
Page 4: ......
Page 16: ...Service Safety Summary xii AWG2021 Service Manual ...
Page 21: ...Specifications ...
Page 22: ......
Page 39: ...Operating Information ...
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Page 60: ...Operating Instructions 2 20 AWG2021 Service Manual ...
Page 61: ...Theory of Operation ...
Page 62: ......
Page 66: ...Theory of Operation 3 4 AWG2021 Service Manual ...
Page 67: ...Performance Verification ...
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Page 123: ...Adjustment Procedures ...
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Page 135: ...Maintenance ...
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Page 144: ...Maintenance 6 8 AWG2021 Service Manual ...
Page 188: ...Removal and Installation Procedures 6 52 AWG2021 Service Manual ...
Page 196: ...Troubleshooting 6 60 AWG2021 Service Manual TP100 5V TP101 GND Figure 6 34 Key Board ...
Page 201: ...Options ...
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Page 222: ...Options and Accessories 7 20 AWG2021 Service Manual ...
Page 223: ...Replaceable Electrical Parts ...
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Page 226: ...Replaceable Electrical Parts 8 2 AWG2021 Service Manual ...
Page 227: ...Diagrams ...
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Page 230: ...Diagrams 9 2 AWG2021 Service Manual ...
Page 236: ...9 8 AWG2021 Service Manual ...
Page 237: ...Replaceable Mechanical Parts ...
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Page 255: ...Replaceable Parts AWG2021 Service Manual 10 17 2 5 1 3 4 A9 2 Figure 10 7 Option 03 ...
Page 257: ...Replaceable Parts AWG2021 Service Manual 10 19 3 1 2 A25 4 Figure 10 8 Option 04 ...
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