1
system’s program code.
This part‘s circuit is relatively simple, if the memory has something wrong, we should
check the SMT’s problem first .IF not the SMT’s problem, we should check the memory’s
supply voltages .Such as the voltage on
C210/206/C219/C220/C221
should be
1.8V，
voltage on
C222/C223/C224
should be 1.2V, the voltage on
C214/C215
should be 0.6V.
There should be a clock signal through the resistor R212.
Memory module‘s supply voltage as below figure 14:
Figure 13 memory’s supply voltage
2.4 Audio module
2.4.1 Microphone circuit
U101 can provide the audio signal’s encode and decode functions for the system. So we
just describe the details on the path out of the U101.
The main microphone was welded on the pads printed on the antenna sub board .The
microphone’s differential signal go through the sub board and FPC, and then arrival the
U101 after through the filter network which can be referred to figure 15.
