Power Supply Circuits - Icom IC-E7 Service Manual

4-4-1 CPU (MAIN UNIT; IC4)-continue
Pin Port
No. Name
Input port for [SQL] key (S7).
75 SQL
"Low": While [SQL] is pushed.
Input port for [FUNC] key (PA BOARD; S1).
76 FUNC
"Low": While [FUNC] is pushed.
Input port for [PTT] key. (PA BOARD; S2)
77 PTT
"Low": While [PTT] is pushed.
Outputs transmit power control signal to the
138 PSET
TX power controller (IC17. pin 3).
Outputs BPFs tracking control signal to the
139 TRAC
tracking varactor diodes driver (Q32).
141 CTCOUT Outputs CTCSS/DTCS signal to the MIC line.
Input port for internal temperature of the
144 TEMP
transceiver.
4-4-2 D/A CONVERTER (MAIN UNIT; IC13)
Pin Port
No. Name
Outputs reference frequency control signal to
1 FSET
the TCXO (X2, pin 1).
Outputs modulation level control signal to the
2 MODSET
modulation volume circuit (Q37).
Outputs DTCS modulation level control signal
3 DTCSET
to the DTCS modulation volume circuit (Q48).
Description
Description

4-5 POWER SUPPLY CIRCUITS

Line
VCC The same voltage as attached battery pack.
Common 3 V converted from VCC line at the
CPU3 regulator (IC11).
CPU3V
The converted voltage is applied to the CPU (IC4),
Re-set IC (IC2), EEPROM (IC1), etc.
Common 3 V converted from VCCline at the +3S
regulator (Q3, Q4) controlled by "+3SC" signal
from CPU (IC4, pin 53) controlled by "PCON" sig-
+3S
nal from the CPU (IC4, pin 52).
The converted voltage is applied to the electric
volume (IC7), VCO BOARD, etc.
Common 3 V converted from VCCline at the +3V
regulator (IC10, Q1).
The converted voltage is applied to the R3v
+3V
regulator (Q6), +10 V DC-DC up-converter (Q7,
Q61, Q62, D3, X4), PLL IC (IC15), D/A converter
(IC13), etc.
Rceive 3 V controlled by R3V regulator (Q6) using
"R3C" signal from the CPU (IC4, pin 44).
R3V
The voltage is applied to the FM IF IC (IC15), 1st
mixer (IC16), 1st IF amplifi er (Q9), RF circuits, etc.
Transmit 3 V controlled by T3 regulator (Q24-Q26)
using "TXC" signal from the CPU (IC4, pin 54).
TX3 The controlled voltage is applied to the TX power
controller IC17, Q31, Q50), pre-driver (PA BOARD;
Q1), microphone amplifi er (IC8), etc.
Common +10 V boosted at the +10V DC-DC up-
converter (Q7, Q61, Q62, D3, X4).
+10V
The boosted voltage is applied to the loop fi lters,
tracking vactor diodes driver (Q32), etc.
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Description