Circuit Instruction; Power Assign And Block Diagram - Hisense MTK8222 Service Manual

4. Circuit instruction

4.1 Power assign and block diagram

Power assign:
Power voltage includes 12V_M、5V_M、5VS and VPA(Voltage Power for Audio, normally
14~16V)，some small size TV's( small than 37 inch) VPA will use 12V_M directly .All other
voltages are converted from the above voltages.
a. 5V_TUNER that power supply for Tuner is converted by U9 from 12_M； The power supply
for panel is converted by chosen output between U31 from 12_M and 5V_M ；The power
supply for the audio IC (U35) of small size TVs is converted by the output of 12V_M connects
ferrite bead and VPA； the last, the 33V rising circuit and mute circuit are converted by the 12_M
directly.
b. Both of the 5VM and 5VS pass through diodes then output 5V_ON，which used for
3.3V/1.2V/DV10 convertion. U36 （DAC） 、 U29/U30 （audio switch） 、 U7 （DAC） 、 U19 （IF ）
and USB are converted from 5V_M directly ；The power supply for DDR(U1,2.6V) is
converted by U11 from 5V_M too
c. 3.3V supply for U17 （ FLASH） ， U14 （ EEPROM） is converted by U4 from 5V_ON . 1.0V supply
for U34 （ the main IC \MT8222） is converted by U3 from the 3.3V ； 1.2V power supply for the
main IC \MT8222. is converted by the 3.3V
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