4
KDC-348U/4751SD/BT41U/BT648U
/U4549/U4549SD/U549BT/X395/X695
COMPONENTS DESCRIPTION
●
ELECTRIC UNIT (X34-696x-xx)
Ref. No.
Application / Function
Operation / Condition / Compatibility
IC1
Power Supply IC
Outputs 5Vx2, 8V, 8.3V, 10.3V, P-CON, P-ANT.
IC21
3.3V AVR IC
Power supply for BU+3.3V to
μ
-COM.
IC51
SW REG
Power supply for D+5.1V to USB and panel.
IC71
Hi-side SW
USB over-current detection.
IC201
System
μ
-COM
Controls FM/AM tuner, CD mechanism, panel, volume.
IC202
Reset IC
Lo when detection voltage goes below 2.8V.
IC203
E2PROM
For log memory.
IC261
iPod Authentication IC
For Apple authentication.
IC301
3.3V to 5V
Level shift.
IC401
E-VOL
Controls the source and volume.
IC501
ATomIC RDS
Tuner IC.
IC601,602
3.3V to 5V
Level shift.
IC801
Power IC
Ampli
fi
es the front L/R and the rear L/R to 50W maximum.
IC802
3.3V to 5V
Level shift.
IC901
BT LPF
Bluetooth output low pass
fi
lter.
IC902
3.3V AVR
Power supply for BT/SD+3.3V.
IC921
Switch IC
MIC switching signal (Panel microphone/ Rear microphone)
Q1,2
SERVO+B AVR
When Q2’s base goes Hi, AVR outputs 7.5V.
Q3,4
Control SW for SERVO+B
ON when Q3’s base goes Hi.
Q5,6
Control SW for IC1
ON when Q5’s base goes Hi.
Q7,8
Control SW for IC1
ON when Q7’s base goes Hi.
Q9,10
Control SW for IC1
ON when Q9’s base goes Hi.
Q51
FREQ CONT SW for IC51
1.1MHz when the base goes Lo, 1.7MHz when the base goes Hi.
Q91,92
4V B AVR
When Q92’s base goes Hi, AVR outputs 12V.
Q93,94
CONT SW for 4V B
ON when Q94’s base goes Hi.
Q101
ACC DET
ON when the base goes Hi during ACC is applied.
Q102
Surge DET
When the base goes Hi, surge voltage is detected.
Q103
BU DET
ON when the base goes Hi during BU is applied.
Q104
Mute CONT
ON when the base goes Hi.
Q301
PAN3.3V SW
ON when the base goes Lo.
Q302
SW3.3V SW
ON when the base goes Lo.
Q701,702
Pre-out Mute SW
When one of 2 bases goes Hi, pre-out is muted.
Q703,704
Pre-out Mute SW
When one of 2 bases goes Hi, pre-out is muted.
Q705,706
Pre-out Mute SW
When one of 2 bases goes Hi, pre-out is muted.
Q707,708
Mute Driver for Pre-out
ON when the base goes Lo.
Q921
MIC SW CONT
Rear MIC when the base goes Lo, panel MIC when the base goes Hi.
Q951
SD3.3V SW
ON when the base goes Lo.
