4
KDC-BT40U/BT645U
KDC-U546BT
COMPONENTS DESCRIPTION
Ref. No.
Application / Function
Operation / Condition / Compatibility
IC5
3.3V
→
5.0V Level Shift
Converts communication signal from 3.3V to 5.0V.
IC6
5.0V
→
3.3V Level Shift
Converts communication signal from 5.0V to 3.3V.
IC7
BU1.5V / BU3.3V Regulator
Power supply for digital back-up.
Power supply for mechanism
μ
-COM.
IC8
E2PROM (Not used)
Memory for ROM correction.
Countermeasure for software malfunction.
IC9
A3.3V Regulator
Power supply for digital, analog and audio line.
Q3
D1.5V Output
The output voltage in which the power supply that diverges from the BU1.5V line
is turned on and off is used as D1.5V.
Q5
B.3.3V Output
The output voltage in which the power supply that diverges from the BU3.3V line
is turned on and off is used as D3.3V.
Q6
Control signal Inverter
Controls Q5.
Q7
APC (Auto Power Control)
Laser diode driver.
Q9
Control signal Inverter
Because the detection logic of LOE/LIM_SW is different in the mechanism
μ
-COM
and the system
μ
-COM, the logic to the mechanism
μ
-COM side is reversed.
D1
Laser Diode Protection
Prevents reverse bias which is applied to laser.
Laser destruction prevention.
D2,3
Countermeasure against Static Elec-
tricity
The potential difference between DGND and AGND is absorbed, and the malfunc-
tion by static electricity is prevented.