FM540 Service Manual
3. Circuit Description
3.1 Overview
This is a FM device.
3.2 Frequency Composition of Circuit
Figure 3-1 Circuit Schematic
The receiver applies secondary mixing technology.The first intermediate frequency is 51.65MHz and the
second one is 450 kHz. The first local oscillator is generated by the frequency synthesizer while the second
one is generated by quadruple frequency of12.8MHz. Txsignal is generated by the frequency synthesizer
and the reference frequency of the frequency synthesizer is generated by TCXO.
ANT SW
RF
AMP
PA
AMP
TX
AMP
PLL
VCO
IF SYSTEM
X4
multiply
TCXO
12.8MHz
51.65MHz
MCF
CODEC
AF
AMP
MIC
CF
450KHz
ANT
MIXER
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Summary of Contents for FM540
Page 1: ...FM540 Service Manual FM540 㔤 ሱ䶒 I ...
Page 89: ...FM540Service Manul Figure 2 FM540 01 Top Layer Position Diagram 136 174MHz Page 86 of 99 ...
Page 90: ...FM540Service Manul Figure 3 FM540 01Bottom Layer Position Diagram 136 174MHz Page 87 of 99 ...
Page 101: ...FM540Service Manul Figure 8 FM540KEYTop Layer Position Diagram Page 98 of 99 ...
Page 102: ...FM540Service Manul Figure 9 FM540KEY Bottom Layer Position Diagram Page 99 of 99 ...