Dc Power Routing - Transceiver Board; Figure 2-1. Dc Power Distribution - Motorola APX 7000 Detailed Service Manual

2-2
Battery
7.5 Volts
(Nominal)
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 – Transceiver Board
NOTE: Refer to
schematics showing the transceiver board DC power routing components.
Connector M101, the B-plus assembly, connects the battery to the transceiver board. Component
E200 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 VOCON
board.
In turn, the VOCON board supplies VSW1 regulated 3.6 Vdc, 2.775 Vdc, and 1.875 Vdc. The
3.6 Vdc supplies regulator U201 and controls switch Q201 which supplies fuse B+ to regulator U200.
The 2.775 Vdc supplies regulator U202, Trident IC U702, 16.8 MHz crystal circuit and Logic
Expander IC U703. The 1.875 sets the logic level for the SPI and SSI data.
The transceiver board 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.
RF Board
M101 FB+
BATT
Fuse
RAW B+
5Vdc
5Vdc
1.875Vdc
3Vdc
3Vdc
1.8 Volts
1.8Vdc
1.5Vdc
1.5Volts
Expansion Board
SW_B+
Audio PA
3Vdc
3Vdc
1.2Vdc
1.2Vdc*
2.8Vdc
2.8Vdc
1.8Vdc
1.8Vdc
Note: ) Not applicable for TI Chipset
*

Figure 2-1. DC Power Distribution

Table 8-1, "Transceiver Schematics and Board Overlays," on page 8-1
Radio Power: DC Power Routing – Transceiver Board
VOCON Board
PMOS
FB+
Switch
P101
5.4Vdc
External SW
1.4Vdc
External SW
1.875Vdc
External SW
3.6Vdc
2.775Vdc
1.875Vdc
1.2Vdc
2.775Vdc
2.775Vdc
2.8Vdc
3.0Vdc
SW_B+
3.3Vdc
3.6Vdc 5Vdc
5Vdc
2.8Vdc
5Vdc
1.875Vdc
SW_B+
3.6Vdc
External
SW
2.23Vdc
External
LDO
MAKO
SW2
2.23Vdc
LD02
2.23Vdc
LDO3
3.6Vdc
LD04
3.6Vdc
LD06
3.6Vdc
LD07
3.6Vdc
LD09
3.6Vdc
LDO10
5.4Vdc
VBUS1
5.4Vdc
VBUS2
SW_B+
LD08
for a listing of