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MODELS: LT-3280D/LT-3780D
3 .
3 .
3 .
3 .
3 . Power circuit
Power circuit
Power circuit
Power circuit
Power circuit
For power supply of LT-3280D and LT-3780D, there are the power supply of “always on” and “ON/OFF” with a
control signal.(Refer to BLOCK POWER.pdf)
(O)IC9A1, IC901(Only 32”) :
Power supply control IC(power factor correction) (FA5500/FA5501 : FUJI)
This IC are control IC for a power factor correction converter using critical conduction mode of
operation. This IC performs a power factor correction by conversion the current waveform from
triangle waveform to sine waveform. This IC and circuit is the same as LT-4260.
(P)IC9A2, IC902(Only 32”) : Power supply voltage control IC (F9222 : FUJI)
This IC controls the power supply voltage by switching about 75KHz.
This IC has MOSFET inside IC, keep switching on and off, and controls its duty to be stable output
voltage. . This IC and circuit is the same as LT-4260.
(Q)IC920(Only 37”) : Power
supply voltage control IC (STR-G9628 : SANKEN)
This IC controls the power supply voltage by switching above 50kHz.
This IC has MOSFET inside IC, keep switching on and off, and controls its frequency to be stable output
voltage. And the duty is determined by input AC power voltage.
PCB
Power
source
signal
Voltage
[V ]
“always on”
or “ON/OFF”
Control
signal
Output
IC
Note
POWER-
SUB1
120V
120V
ON/OFF
Psave1
For
inverter.
Only 37”
POWER-
SUB2
24V
24
ON/OFF
Psave1
For inverter.
Only 32”
24V
24
always on
-
For MAIN
18V
18
ON/OFF
Psave4
IC9B5
Only 37”
P5V
5
ON/OFF
Psave4
IC9B6
Only 32”
S8V
8
always on
-
IC9B4
S5V
5
always on
-
IC9B7
S3.3V
3.3
always on
-
IC830
AMPVC
C
17
ON/OFF
Psave3
IC9B3
4.5V
4.5
ON/OFF
Psave2
IC9B2
A3.3V
3.3
ON/OFF
Psave2
IC9000
D3.3V
3.3
ON/OFF
Psave2
IC9010
AD3.3V
3.3
ON/OFF
Psave2
IC9020
D2.5V
2.5
ON/OFF
Psave2.5 IC9030
A1.8V
1.8
ON/OFF
Psave2.5 IC9040
POWER
MAIN
Summary of Contents for LT-3280
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Page 4: ...MODELS LT 3280D LT 3780D Page 4 ...
Page 6: ...Page 6 MODELS LT 3280D LT 3780D ...
