Hytera PD362, Service Manual

Page: 92 / 141

Uc (430
‐
470 MHz)
Circuit Description
17
)LQDOO\ the audio signal is output to audio amplifier MAX9716EUA for amplifying via the HPL/R port of
TLV320AIC3204 to drive the speaker.

TX path
The audio signal UHFHLY ed by the MIC is divided into two paths: one path is processed and sent to MCU
for VOX sampling; the other path is sent to TLV320AIC3204 for AGC amplifying. After AD conversion,
the signal is sent to SCT3928 via I2S interface for internal processing. Then the signal is sent to
TLV320AIC3204 via I2S interface for DA conversion and amplifying. Finally, the audio signal is output to
FGU for two-path modulation via the LOL/R port of TLV320AIC3204.

External Connector

Earpiece connector:
Ф
2.5mm standard earpiece connector for specific earpiece.

USB port: It is used for battery charging and programming.
Audio Amplifier
Main parameters of MAX9716EUA are listed in the table below:
5.2
RF Section
5.2.1
Transmitter Circuit
The transmitter circuit is mainly composed of:

RF Power Amplifier Circuit

Low-pass Filter Circuit (for suppressing harmonics)

Auto Power Control Circuit (APC)
Rated Power (P
o
) 0.4W R
L
=8 Ω
Maximum Power (P
max
) 0.8W R
L
=8 Ω