2-2
Radio Power:
DC Power Routing
Figure 2-1. DC Power Distribution
B+ from the battery is electrically switched to most of the radio, rather than routed through the On/
Off/ switch. The electrical switching of B+ supports a
keep-alive
mode. Under software control, even
when the On/Off switch has been turned to the Off position, power remains on until the MCU
completes its power-down, at which time the radio is physically powered down.
2.2
DC Power Routing
NOTE:
Refer to List of Transceiver Schematics and Board Overlays for a listing of schematics
showing the transceiver board DC power routing components.
Connector M101, the B-plus assembly, connects the battery to the main board. Component E201
forms a power-line filter for signal DC_ RAW_B+, which supplies battery voltage to the transmitter
section. Fuse F200 and filter C202, L200, C203 supply fused B plus to the controller section.
In turn, the controller supplies VSW1 regulated 3.6 Vdc, 2.78 Vdc, and 1.85 Vdc. The
3.6 Vdc supplies regulator U201 and controls switch Q201 which supplies fuse B+ to regulator U200.
Regulator U201 supplies regulator U202. The 2.775 Vdc supplies regulator U202, Trident IC U702,
and 16.8 MHz crystal circuit. The 1.85 sets the logic level for the SPI and SSI data.
In addition, the main board also has four regulators 5 Vdc (U200), 3 Vdc (U201), 1.8 Vdc (U202) and
1.5 Vdc (U203). The 5 volt regulator supplies the FGU section, transmitter ALC and receiver back
end. The 3 volt regulator supplies dc for the receiver front ends, mixer, receiver back end and GPS.
The 1.8 volt regulator supplies dc for the receiver front end and mixer. The 1.5 volt regulator supplies
dc for the buffers in the FGU section.
Fuse
5Vdc
3Vdc
Battery
7.5 Volts
(Nominal)
Main Board
1.8Vdc
1.5Vdc
BATT
M101
RAW B+
3Vdc
1.8 Volts
1.5Volts
FB+
3.6Vdc
1.85Vdc
PMOS
Switch
SW_B+
MAKO
SW2
LD02
LDO3
LD04
LD06
LD07
LD09
LDO10
VBUS1
VBUS2
LD08
External SW
External SW
External LDO
1.875Vdc
1.55Vdc
2.775Vdc
2.775Vdc
2.8Vdc
2.8Vdc
3.0Vdc
3.3Vdc
5Vdc
5Vdc
5.4Vdc
1.4Vdc
1.85Vdc
External
LDO
3.6Vdc
2.23Vdc
5.4Vdc
5.4Vdc
SW_B+
2.23Vdc
5Vdc
FB+
3.6Vdc
3.6Vdc
3.6Vdc
2.23Vdc
3.6Vdc
External
SW
3.6Vdc
1.85Vdc
3.6Vdc
5.4Vdc
5.4Vdc
2.775Vdc
3.3Vdc
2.8Vdc
3.3Vdc
2.8Vdc
5Vdc
Audio PA
Summary of Contents for Astro APX 3000
Page 1: ...APXTM TWO WAY RADIOS APX 3000 DETAILED SERVICE MANUAL ...
Page 2: ......
Page 4: ...Notes ...
Page 6: ...vi Document History Notes ...
Page 10: ...x Table of Contents Notes ...
Page 12: ...xii List of Tables Notes ...
Page 18: ...xviii List of Figures Notes ...
Page 22: ...xxii CommercialWarranty Notes ...
Page 46: ...3 20 Theory of Operation Main Board Notes ...
Page 84: ...3 58 Theory of Operation Bluetooth Notes ...
Page 208: ...6 64 Troubleshooting Waveforms LF CW on Spectrum Analyzer Notes ...
Page 222: ...7 14 Troubleshooting Tables List of Board and IC Signals Notes ...
Page 282: ...8 60 Schematics Boards Overlays and Parts Lists Main Board Block UHF1 84012513001_A Notes ...
Page 390: ...8 168 Schematics Boards Overlays and Parts Lists Main Board Block VHF 84012512001_A Notes ...
Page 456: ...9 8 Debugging Fixture Powering up Covert Board Notes ...
Page 468: ...Glossary 10 Glossary Notes ...
Page 472: ...Index 4 Index Notes ...
Page 473: ......