Page 72 - Electronic Mechanic - TP - Volume - 2
P. 72

ELECTRONICS MECHANIC - CITS




           Path IC

           When you check your mobile phone PCB ,you will be unable to find these ICs quickly. But when you un mount these
           ICs you can easily identify that following images will be help full for understanding about its external appearance.

           Majority ,Power Amp and Antenna Switch are come
           as this type of IC.
           MBGA(Micro Ball Grid Array)
           The  BGA  is  descended  from  the  pin  grid  array
           (PGA), which is a package with one face covered
           (or partly covered) with pins in a grid pattern. These
           pins conduct electrical signals from the integrated
           circuit to the printed circuit board (PCB) onwhich it
           is placed. In a BGA, the pins are replaced by balls
           of solder stuck to the bottom of the package.


           List of major mobile phone intergrated circuit with their functions and faults
           Check following list of ICs and try to understand about that faults.
           •  Power Amp

           •  Antenna Switch
           •  RF Processor(hagarIC)
           •  Power IC
           •  CPU

           •  Charging IC
           •  Flash IC(ROM orEEPROM)
           •  Oscillator(VCO)
           •  Sim IC
           •  Key Pad IC
           •  LCD Light control IC

           Power Amp
           This is a very important IC for Transmitting signal(Tx) in your phone. This IC is work as a Tx amplifier and it get
           high voltage directly from the battery. When it is damage we can see following faults.













           i  Signal Drop

           ii  No Network or Access
           iii  Battery low quickly
           iv  Can’t make a call (Tx not work properly)
           v  Power on failure
           vi  Phone will heat



                                                           55

                                    CITS : E & H - Electronics Mechanic  - Exercise 134
   67   68   69   70   71   72   73   74   75   76   77