VHF (136-174 MHz)
Circuit Description
19
DSP for processing. Then the signal is sent to DAC (TLV5614), which converts the signal to modulation
signal. After modulated and amplified in the RF module, the signal is sent out from the antenna.
The RF signal received by the RF module is converted to digital signal by ADC (AD9864), and is then
sent to DSP for demodulation and processing. Then the digital signal is sent to the digital audio
processor of the codec for digital audio processing, and is then converted into analog audio signal by
DAC of the codec. Finally the signal is amplified by the external audio amplifier (TDA2822) to drive the
speaker, and the audio signal is output.
OMAP5912
Audio is processed via DSP
UWIRE.SCLK
UWIRE.CS3
UWIRE.SDO
UWIRE.SDI
MCLK
MCBSP1.DR
MCBSP1.FSX
MCBSP1.DX
MCBSP1.CLKX
TLV5604
DAC
AD9864
MCBSP2.DX
DIN
DOUTA
MCBSP2.DR
RF TX
RF RX
MIC Input
APA
TDA2822D
Gain: 31dB
Speaker Output
RX
TX
MIC
Gain:
13dB
Audio Amplifier
Main parameters of TDA2822 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
)
0.5 W
R
L
=16
Ω
Maximum Power (P
max
)
1.6 W
R
L
=16
Ω
Summary of Contents for PD502
Page 1: ...PORTABLE...
Page 5: ...VHF 136 174 MHz...
Page 13: ...VHF 136 174 MHz Exploded View and Packaging Guide 7 3 2 Packaging Guide...
Page 18: ...VHF 136 174 MHz Circuit Description 12...
Page 43: ...PCB 3 9 PCB VHF 136 174 MHz...
Page 44: ...PCB 3 VHF 136 174 MHz...
Page 71: ...UHF1 400 470 MHz...
Page 79: ...UHF1 400 470MHz Exploded View and Packaging Guide 7 3 2 Packaging Guide...
Page 84: ...UHF1 400 470MHz Circuit Description 12...
Page 108: ...UHF1 400 470MHz PCB 36 9 PCB...
Page 109: ...UHF1 400 470MHz PCB 37...
Page 136: ...1616300000260 2014 03 17 L07157 4...