APEX
™
Exciter Incorporating FLO
™
Technologyr
DC Power Distribution
Theory of Operation
26
04s40
0.fm
03/08/07
888-2604-001
Page: 4-15
WARNING: Disconnect primary power prior to servicing.
The following are the controller board status screen entries:
• +3.3 Vdc: This is the output of the 3.3 V dc to dc converter.
• +5 Vdc: This is the board input voltage.
RTC battery: (OK or FAULT) This is the battery required for the real time clock.
4.5.2.2
FPGA Modulator Board Power
The following supply voltages are listed as modulator board status screen entries:
• 5 Vdc: This is the board input voltage, which comes from the controller board via J10.
Except for the 1.8 volt supply, it supplies power to the other dc to dc converters men-
tioned below.
• 3.3 Vdc: This is the output of the 3.3 V dc to dc converter.
• 2.5 Vdc: This is the output of the 2.5 V dc to dc converter.
• 1.8 Vdc This is the output of the 1.8 V dc to dc converter, which is supplied by the 3.3
volt supply.
• 1.2 Vdc This is the output of the 1.2 V dc to dc converter.
• GPS 5 Vdc refers to the 5 volt supply for the GPS receiver.
4.5.2.3
Adaptive Processing Board Power
The adaptive precorrector board re5 VDC from the controller board. This is the 5
Vdc entry on the screen.
The +5 Vdc also operates three dc to dc converters which supply the +3.3 Vdc, +1.9 Vdc,
and the +1.8 Vdc voltages.
+5 Vdc and +3.3 Vdc are supplied to the D/A converter and the A/D converter.
The following are the adaptive processing board screen entries:
• +3.3 Vdc: This is the output of the 3.3 V dc to dc converter.
• +5 Vdc: This is the board input voltage.
• AP 3.3 Vdc supply (referred to as the AP_IOVDD supply) is derived from the 3.3
Vdc supply through an FET switch. This voltage is switched off if the 1.9 Vdc AP
supply faults.
• AP 1.9 Vdc: This is the output from the AP DSP core supply dc to dc converter
• NL 3.3 Vdc supply (referred to as the NL_IOVDD supply) is derived from the 3.3
Vdc supply through an FET switch. This voltage is switched off if the 1.8 Vdc NL
supply faults.
• NL 1.8 Vdc NL DSP core power supply.
4.5.2.4
Power for DAC and ADC Boards
5 Vdc and +3.3 Vdc are supplied to the DAC (digital to analog converter) and ADC (analog
to digital converter) from the adaptive corrector board.