Power Supply; On-Screen Circuit; Video Input Circuit; Definition Converter Lsi Peripheral Circuit - HP VF15 Service Manual

3. Power supply (Circuit diagrams Main PWB)
3.1 Line filter consists of FB326, FB327, FB328. It eliminates high frequency interference to meet EMI's requirement.
3.2 I309 3.3V and 2.5V DC-DC requlator
A 3.3V and 2.5V DC power supply for LCD module and ASIC.
3.3 A 9.2V DC power supply for LCD module source IC is generated from I311.
3.4 A 6V DC power supply for LCD module to control gate IC OFF is generated from I311.
3.5 A 18V DC power supply for LCD module to control gate IC ON is generated from I311.
3.6 A 3.6V DC power supply for LCD module to control panel Gamut of V-Com.
4. On-screen circuit (Circuit diagrams Main PWB)
I303 (gm2115) Embeded function.
On-screen menu screen is established and the resultant data are output from I303 (Circuit diagram MAIN PWB ,
gm2115).
5. Video input circuit (Circuit diagram MAIN PWB)
The AC-coupled video signal is used to clamp the black level at 0V).
6. Definition converter LSI peripheral circuit (Circuit diagram MAIN PWB)
I303 gm2115 is the definition converter LSI.
The analog R, G, B signal input entered from the video input circuit is converted into the digital data of video
signal through the incorporated A/D converter. Based on this conversion, this device performs interpolation
during pixel extension. The source voltage for this device is 3.3V and 2.5V the system clock frequency is 14.
318MHz.
The withstand voltage level for the input signal voltage is 3.3V and 5V.
7. System reset, LED control circuit (Circuit diagram MAIN PWB)
7.1 System reset
System reset is performed by detecting the rising of the 5V source voltage at I305.
7.2 LED control circuit
Green / amber is lit with the control signal of the LED GREEN and LED AMBER signal pin 49, 48 from I303 (Circuit
diagram MAIN PWB).
vf15 / FP15 / f1523 / FP5315
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