Baseband Section; Power Section; Figure 4-1 Diagram Of Power Distribution - Hytera MD78X Service Manual

Service Manual

4. Baseband Section

4.1

Power Section

Auto baterry Voltage
13.6±15%
ON\OFF KEY PWB
IGN_SENCE
EMERGENCY
Both the baseband control IC and the RF section can convert the supplied voltage to an appropriate
one via the voltage converter.
 Supply for RF: U914, Q920 and Q921 supply power for the RF section by high current PNP transistor
and comparator, which can work as LDO (Low Dropout Regulator).
 Supply for FGU: U918 and U915 supply 3.3V and 5V respectively to U100.
9V3A
Q920\Q921\U914
U902
U913

Figure 4-1 Diagram of Power Distribution

7
Q802\Q803\U201
Q804\Q805
9V1A
Q801
9V1A
Q902
U703
U702
U915
Q104
5VA
U918
3V3A
5VA
U905
3V3A
U909
1V6D
U919
5VD
U302
3V3D
U900 U233
U910
U231
1V8D
U903 U232
U302
3V3DP
U326
U901
J400
3VRTC
U912
Baseband Section
Q801
Q6102
Q6103
U6000
Q6105
5VA
U701
U701
4V3A
Q100\Q103\Q106\Q110
U100
X100
U500
U231
X302
U302
U401 USB
Control Head
Accessory Level
Translator
Option board
U323
U326