Ipl42L Psu Block Diagram - Philips 32PFL3404/77 Service Manual

EN 24 7. TCM3.1L LA
7.3.3 IPL42L PSU
Block Diagram
P F C o u tp u t
A C
P F C IC
R e la y
In p u t
L6562A
(ST)
P S -O N
Figure 7-4 Block diagram IPL42L PSU
Key Components
The key component ICs are:
• Stand-by power supply IC: FSQ510 (Fairchild).
• PFC control IC: L6562 (ST).
• 24V PWM control IC: FA5571N (FUJI).
• Inverter high voltage control IC: OZ9926 (O2).
Control Signals
Table 7-4 Control signals
Control signal
PS-ON
BL_ON 5.0V >= ON >= 2.0V The inverter is working
Burst dimming freq. / duty
PWM Dimming
Output Characteristics
Table 7-5 Output characteristics
Output Voltage Tolerance Min. current Max. current
+3V3 +/- 5%
24V +/- 5%
Fault Finding
Normal PSU working order:
• Connect the 220V AC power plug.
• The 3.3V Stand-by power supply (Stand-by uP U801) will
start. This is a "single-ended flyback regulator". For a good
functioning of this part, check the availability of 1.25V on
U803 (TL431).
• On connector P802, signal line "PS_ON" will go "high"
(3V3) and relay K801 will be activated.
• Also capacitors C811/C812 will be charged, supplying
IC806 with electricity. This will start the PFC circuit and
generate the +24 V control.
• Now, IC805 will start, and will generated the 24V output.
• On connector P802, signal "DIM" sets the PWM dimming
status.
• On connector P802, when signal "BL-ON" goes "high", the
high voltage Inverter (IC901, OZ9926A) will start.
2009-Jun-05
Circuit Descriptions
D IM
IN V E R T E R
3 9 5 V
IC OZ9926A
(O2)
E NA B LE
S w itc h c o n tro l
B L-O N
Vo lta g e D e te c t
P W M P ow er
S upply IC
FA 5571
(F U JI)
S T B P ow er
S upply IC
F S Q 510
(FA IR C H ILD
18520_214_090319.eps
Comments Output
5.0V >= ON >= 2.0V AC power output ON
1.0V >= OFF >= 0V AC power output OFF
1.0V >= OFF >= 0V The inverter is switched OFF
100 - 200 Hz / 10 - 100%
High level: 2V ~ 5.0V
Low level: 0V ~ 0.7V
Load regulation
5 mA 300 mA +/- 5%
0.5 A 2.5 A +/- 5%
+H V
- H V
2 4 V
3 .3 V
090319