5
KDV-S210P/S220P
/S230P/S240P
COMPONENTS DESCRIPTION
Ref. No.
Application / Function
Operation / Condition / Compatibility
UP2
S7V generation switching regulator IC
Power supply is input from No. 2 pin and switching output is made from No. 3 pin.
Going via choke coil, it becomes S7V power supply output.
UP3
Analog audio output LPF amplifier
CH1-side is Rch and CH2-side is Lch. Constitutes non-inverse active LPF composition.
UP4
Composite video output 75
Ω
driver
Input is made on No. 3 pin and output is made from No 6 pin.
amplifier IC
QP1
Mute circuit driving TR
When QP2 is ON, input is made to the emitter. Mute circuit driving power supply is output
from the collector.
QP2
Mute circuit switching TR
When this TR comes ON, muting is ON and when it comes OFF, muting is OFF.
QP3
Mute circuit switching TR
This is a TR for switching QP2. Therefore, the logic is inverted and when the TR comes
ON, muting is OFF, and when the TR comes OFF, the muting is ON.
QP4
Rch mute TR
When base is H, Rch is muted.
QP5
Lch mute TR
When base is H, Lch is muted.
QP8
Composite video output buffer driver TR
When the input signal comes in on the base, output is made from the emitter.
QP9
Power supply ON/OFF delay circuit SW TR
When this TR is ON, base current of QP21 is shut off. QP21 is OFF and switching power
supply is ON.
QP10
Mute circuit switching TR
When Z_MUTE signal in the base of this TR is active, (H on no signal), QP1 is turned ON
and the mute circuit is driven.
QP11
Mute circuit switching TR
/P_ON in the base becomes L when the power switch comes ON. Therefore, it is H when
the power is OFF. When this happens, QP3 is forced to go OFF and muting is driven.
QP12
Power supply ON/OFF delay circuit SW TR
On the base of this TR, power switch triggered /P_ON signal comes in. When this is L, and QP22
is turned ON, base current of QP20 is shut off. When QP20 is OFF, switching power supply is ON.
QP15
Reduced voltage detection switching
At the time of rB1, base current is shut off and the circuit goes OFF.
TR for resume operation
QP20
Power supply ON/OFF delay circuit SW TR
When this TR is ON, switching power supply is OFF.
QP21
Power supply ON/OFF delay circuit SW TR
When this TR is ON, switching power supply is OFF.
QP22
Power supply ON/OFF delay circuit SW TR
When this TR is ON, base current at QP20 is shut off. This means QP20 is OFF and
switching power supply is ON.
QP30
BU_VCC (+5V) regulator driving TR
Receives batter power supply (+B1) by the collector and outputs regulation voltage 28V
(+B1) from the emitter.
QP40
28V regulator drive TR
Receives battery current (+B) with collector and outputs regulated voltage 28V (+B1) from the
emitter. This is used to counter the surge current, and it is normally about +B - +B1 = 1.4V.
QP41
TR for comprising Darlington connection
Along with QP40, constitutes Darlington connection and works to enhance compound hfe.