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10.
Inverter
This unit operates on an output voltage of 15V from power source.
10.1
Regulator: Q101 get a +5VDC for I102 power supply.
10.2
UVP: Q106 turns off when the Vin is under 14V. Then pin 3 of I102 is pulled low and inverter off immediately.
That is the under voltage protection.
10.3
Control IC: I102 (OZ960S)
10.3.1 Enable : When pin 3 of I102 is over 1.5V, I102 works. If it is under 1.5V, I10 2 turns off.
10.3.2 OSC: When I102 enabled, R108/C115 (pin 17/pin18 of I102) determine the operating frequency.
10.3.3 SST: C104 (pin 4 of I102) provides soft start function.
10.3.4 Ignition: R109 (pin 8 of I102) provides higher operating frequency for more striking voltage until regulation
of feedback of lamp current. C103 (pin 1 of I102) determine the striking time.
10.3.5 Dimming control: The divided voltage of R106/R105/R104 control the duty pulse of burst-mode to drive Q105
and perform a wide dimming co ntrol for the CCFL. The burst-mode frequency is determined by C116.
10.3.6 Regulation: Pin 9/pin 10 of I102 provide regulation of the CCFL current from feedback. The non-inverting
reference (pin 10 of I102) is at 1.25 V nominal.
10.3.7 Protection: Open-lamp protection in the ignition period is provided through both pin1 and pin 2 of I102.
Removal of the CCFL during normal operation wil l trigger Q104 to turns on and shuts off the inverter. This
is latch function.
10.3.8 Output drivers: The configuration prevents any shoot-through issue associated with bridge-type power
conversion applications. Adjusting the overl ap conduction between I101 P-MOSFET and I103 N-MOSFET,
I101 N-MOSFET and I103 P-MOSFET, the CCFL curren t regulation is achieved.
10.4 Full-bridge swit ching/Transformer: I101/I103 /C123/C125/T101/T102 compose full-bridge swit ching to
convert DC int o AC for driver the CCFL.
10.5
Detection: C124/C119/CR102 detect the output voltage and ensure a rated voltage by pin2 of I102. Q102/Q103
ensure not a o pen-lamp.
10.6
Feedback: CR101/R120/R121/D108 sense the lamp current for negative feedback and regulation. The divided
voltage on R121 will be at 1.25V.
VCC
Regulator
ON / OFF
U.V.P.
Brightness
control
Page 8
Inverter Board Block Diagram
VDD
Control IC : OZ960
Enable
Output driver
OSC
Protection
SST
Ignition
Dimming
Regulation
control
H15AAX (AL502)
Full-bridge switching
Transformer
Detection
Feed back
Circuit Description
Lamp
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