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 Amplifi 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 amplifi 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