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Keysight N9923A Service Guide 5-15
Theory of Operation
Grounding and Power
Grounding and Power
Grounding
Each printed circuit board has a single ground plane. The ground planes on the
A4 RF board and A5 system board are connected via the common shields at
multiple points. The ground plane on the A3 front panel interface board is
connected to the ground plane on the A5 system board.
There are no separate grounds in the analyzer. There is no “star” ground point
in the analyzer.
Batt Neg and Ext DC neg are connected to the A5 system board ground plane.
The A2 LCD assembly has two separate grounding circuits: the LCD power and
control circuits and the backlight LED’s.
— The LCD power and control circuits share a ground that is connected to the
ground plane on the A5 system board.
— The ground for the backlight LED’s is connected to the ground plane on the
A3 front panel interface board.
Voltages and Power Supplies
The following power supplies exist within the analyzer:
— Digital 5 volts—generated from Unreg DC on the A3 front panel interface
board, controlled by the System Monitor on the A5 system board, and used
on the A3, A4, and A5 boards.
— Digital 3.3 volts—generated from Unreg DC on the A3 front panel interface
board, on/off functions controlled by the System Monitor on the A5 system
board, and used on the A2 LCD assembly and A3, A4, A5, and A6 boards.
— Analog supply voltages—seven separate voltages generated from Unreg DC
on the A5 system board, on/off functions controlled by the System Monitor
on the A5 system board.
— LCD backlight voltage—generated on the A3 front panel interface board
from the digital 5 volt supply voltage.
— Power for the System Monitor circuit—3.3 volt circuit powered from Ext DC
or Batt +, whichever is greater. Used on A5 system board only.
— Unreg DC—from Ext DC or Batt +, 21 volts max.
— Ext DC—from external Power AC Adapter, nominal 15 volts, acceptable up
to 19 volts.
— Batt + —from main battery, nominal 12 volts.
All voltages except Ext DC, Batt +, and the System Monitor power can be
turned on/off within the analyzer. Refer to
“Power Management Circuitry” on
for more information.
Содержание N9923A
Страница 1: ...Service Guide Keysight N9923A FieldFox RF Vector Network Analyzer 2 MHz 4 GHz 2 MHz 6 GHz ...
Страница 23: ...2 8 Keysight N9923A Service Guide General Product Information Keysight Support Services and Assistance 2 ...
Страница 33: ...3 10 Keysight N9923A Service Guide Tests and Adjustments Test Software and Information Available on the Web 3 ...
Страница 81: ...6 14 Keysight N9923A Service Guide Replaceable Parts Replaceable Parts Listings 6 ...