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/volume control knob, S2. The electrical switching of B+ supports a
keep-alive
mode. Under
software control, even when the On/Off/volume control knob 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
Table 8-1
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
Keypad Board
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 APX 2000
Page 1: ...APXTM TWO WAY RADIOS APX 1000 APX 2000 APX 4000 APX 4000Li DETAILED SERVICE MANUAL ...
Page 4: ......
Page 6: ...iv Document History Notes ...
Page 8: ...Notes vi Commercial Warranty ...
Page 10: ...Notes ...
Page 22: ...xiv List of Figures Notes ...
Page 226: ...6 64 Troubleshooting Waveforms LF CW on Spectrum Analyzer Notes ...
Page 688: ...Index 4 Index Notes ...
Page 690: ...ii Notes ...
Page 700: ...xvi List of Figures Notes ...
Page 806: ...5 50 Troubleshooting Charts PA Failure Notes ...
Page 1008: ...8 178 Schematics Boards Overlays and Parts Lists Transceiver RF Boards UHF2 84012621001 Notes ...
Page 1062: ...8 234 Schematics Boards Overlays and Parts Lists Keypad Board M2 and M3 PC000261A01 Notes ...
Page 1064: ...ii Notes ...
Page 1068: ...Notes A 4 EMEA Warranty Service and Technical Support Further Assistance From Motorola ...
Page 1090: ...Glossary 10 Glossary Notes ...
Page 1094: ...Index 4 Index Notes ...
Page 1095: ......