4
KDC-BT6544U/BT6544UY
/BT7043U/BT742U
●
ELECTRIC UNIT (X34-629x-xx)
Ref. No.
Application / Function
Operation / Condition / Compatibility
IC10
Audio 8V REF / Power Supply
Outputs 1.27V.
IC70
Digital AVR for Panel & USB
Switching regulator for USB&VBUS and FDC (5V).
IC150
Power Control SW
USB power control switch with over current detection and protection.
IC200
Power IC
Ampli
fi
es front L/R and rear L/R.
IC240
DSP
Digital signal processor.
IC241
E2P Memory
DSP setting memory.
IC260
Source Selector & E-VOL
Selects analog source & full source volume. Analog source: AM/FM, CH, AUX.
Digital source is selected by CD mecha. (CD/USB)
Speaker-out “DC-offset” detection and protection. (This function consists of
IC260 and IC200)
IC301
System
μ
-COM Reset Control
Outputs Lo (system
μ
-COM reset) when detection voltage goes below 3.6V.
IC302
System
μ
-COM
System control including power management, panel control, AM/FM/CH/SOC
control, external control and etc.
IC303
Mute Logic
Controls logic for muting.
IC500
RDS & RBDS Decoder
IC600
Bluetooth MIC Buffer
MIC signal differential ampli
fi
er.
IC601
Bluetooth Module 3.3V AVR
During active time, POWER is ON.
Q10~12
Audio 8V AVR
During active time, POWER is ON.
Q20~23
DSP5V AVR
When the base of Q23 goes Hi, DSP5V AVR is ON.
Q30,31
SW5V
During active time, POWER is ON.
Q32,33
BU5V AVR
During active time, POWER is ON.
Q40~43
Servo AVR
During active time, POWER is ON.
Q50~53
ILLUMI AVR
During active time, POWER is ON.
Q90
BU DET SW
Detects the backup voltage. If the backup is detected, it is ON.
Q92
ACC DET SW
Detects ACC voltage. If ACC is detected, it is ON.
Q93
Surge DET SW
Detects over-input voltage. If surge is detected, it is ON.
Q110~113
Power Cntrol Output
When the base of Q110 goes Hi, power control output is ON. During active time,
audio source is active.
Q114,115
Power ANT SW
During active time, tuner source is active.
Q130
Small Lamp DET SW
Detects small lamp. If small lamp is detected, it in ON.
Q170
Level Shift
Sysytem
μ
-COM (5V)
↔
Bluetooth module (3.3V)
Q440
Preout Mute SW
Non-fader Lch
Q441
Preout Mute Driver
(Non-fader) When this transistor is ON, mute is active.
Q442
Preout Mute SW
Non-fader Rch
Q450
Preout Mute SW
Front Lch
Q451
Preout Mute SW
Front Rch
Q460
Preout Mute SW
Rear Lch
Q461
Preout Mute Driver
(F/R) When this transistor is ON, mute is active.
Q462
Preout Mute SW
Rear Rch
Q480,481
AM+B SW
During active time, AM source is active.
Q520
PAN5V SW
When the base goes Lo, PAN5V is ON.
Q601
Bluetooth Module Reset
When the base goes Hi, Bluetooth module is reset.
COMPONENTS DESCRIPTION
