Power Supply Circuits - Icom IC-E2820 Service Manual

4-4 POWER SUPPLY CIRCUITS

Voltage from the power supply is routed to whole of the circuit in the transceiver via switches and regulators.
MAIN UNIT
NOISE
FILTER
IC21
5V
REG
VCC
REG
Q82
PWR
PWR
CTRL
HV
IC55,
D164
IDET
CURRENT
DETECT
CPU5V
NOISE
FIL
Q83,
D119
5VS
5VS
REG
Q84, D120
L5V
5VS
REG
5V
Limitter (D165−D168), etc.
Q81 IC24
AF filter (Q47, Q50),
8V
+8
MIC amplifier (IC28),
REG
APC controller (IC4), etc.
VCC
AF power amplifier (IC38)
HV
TX power
amplifiers (IC2, IC3)
CPU (IC25)
(for current monitoring)
CPU (IC25),
EEPROM (IC22),
Reset IC (IC23), etc.
PLL ICs (IC14, IC41),
D/A converter (IC8),
ALC IC (IC32), etc.
DTMF decoder (IC56),
Electric volume (IC33),
AF mixer (IC59), etc.
4 - 8
IC3
+5 +3
REG REG
CPU (IC13),
+3.2V
Regulator (Q14, Q15),
Protector/Buffer (IC12), etc.
Reset IC (IC9),
5V
LCD module, etc.
CONTROL UNIT