tecsun: Tecsun PL-880 - Technical details
ID: 575404
tecsun: Tecsun PL-880 - Technical details
02.Jun.22 17:45
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The Tecsun PL-880 uses two PCB assemblies:
- MCU/DISPLAY/KB PCB Assembly identified as "PL-880-B-REV.n"
- Receiver PCB Assembly identified as "PL-880-A-REV.n"
- where "n" is the release number.
The followwing partial parts listing with remarks covers the PCB assemblies for the MCU "PL-880-B-REV.10" and Receiver PCB "PL-880-A-REV.12". Component labels of MCU PCB are prefixed with "2" as seen on the board silkscreen labels.
MCU PCB "PL-880-B-REV.10"
- Power Control
- 2D2 BAS140W schottky diode - From VCC to IC3
- 2IC3 RH5Z27CA? 3-pin smd LDO power regulator - From VCC to Power lines
- 2Q5 SE2301 3-pin smd MOSFET - Switch Power on/off
- 2D1 LED LCD backlight
- 2Q2 S9014 3-pin smd npn - Switch for 2D1 LED on/off
- 2C4 Super Capacitor
- DSP processor
- IC4 Si4735-D60 DSP receiver - FM RF signal decoding, MW/SW 10700 kHz IF signal decoding
- MCU Processor
- 2IC1 R5F2L38ACDFP Renesas 96KB ROM, 1KBx4 Data Flash, 10KB RAM, MCU processor in 80-pin PLQP0080KB-A smd package
- 2IC2 BL24C256 256Kbit Serial EEPROM 8-pin smd
Receiver PCB "PL-880-A-REV.12"
- RF Front-End
- D1, D2 1N4148 diodes - Antenna over-voltage protection
- Q26 BF510 3-pin FET smd - MW RF front-end
- Q4 2SK2394-Y7 3-pin FET smd - SW RF front-end
- D6, D5 1SS135 smd diodes - Join MW RF andd SW RF signals to send to 1st Mixer
- Q6, Q5 L8050HQLT1 3-pin smd npn - Enabless "DNR1" AGC line to control RF gain by inserting C12 between D6,D5 outputs and ground.
- 1st and 2nd Mixers
- Q7, Q8 2SK2394-Y7 3-pin FET smd - 1st Mixer with 55845 kHz IF output
- Q9 BF510 3-pin smd - 2nd Mixer with 10700 kHz IF output
- 1st Local Oscillator
- Q16 BF510 3-pin FET smd - Oscillator
- Q17 2SC3356 3-pin npn smd - buffer
- D9, D10 1SV101 smd varicaps
- 2nd Local Oscillator
- Q13 2SC3356 3-pin smd npn - Oscillator
- 1X2 45.145 MHz xtal
- D11 1SV101 varicap
- D12 BB133 varicap
- PLL Synthesizer
- IC6 MB15E03SLPFV1 16-pin smd - PLL Synthesizer
- 1X3 7.200 MHZ xtal
- Dynamic Noise Reduction (DNR)
- Q12 2SK2394-Y7 3-pin FET smd - 10700 kHz IF buffer
- IC4 CXA1691AM (CD1691CB) 28-pin smd AM/FM radio - Receives MW/SW 10700kHz IF signal, outputs AGC voltage at pin 22 marked as "DNR1" to
control the gainenable a low pass filter on the RF Input front-end. - Q20, Q21 S9014 3-pin smd npn - Together with VR3 500K pot, receives "DNR1" AGC and outputs distinct AGC level marked as "DNR2" to control filter response of the Audio Amplifier.
- 1X5 10.245 kHz xtal
- LBQ1 455 kHZ filter
- DC-DC Converter for tuning voltage
- Q23, Q24 S9014 3-pin npn smd - Oscillator, using transformer T881
- D8 1N4148 smd - HF rectifier
- D7 16V Zener diode smd - Regulation
- Power Supply
- D4 1N5819 schottky diode - From USB Power to VCC line
- Q20 2SJ245 3-pin smd MOSFET - Switch from BATT power to VCC line
- BT1 3.7V Battery
- Q14 SE2301 3-pin smd MOSFET - Battery charger circuit
- IC1 MCP73831 (or equiv.) 5-pin smd SOT23-5 - BT1 Battery charger
- IC2 RP114N281D 5-pin smd LDO 300mA, 2.8V power regulator
- Q10 SE2301 3-pin smd MOSFET - Switch to SW-Power
- Q11 SE2301 3-pin smd MOSFET - Switch to MW-Power
- Q2 SE2301 3-pin smd MOSFET - Switch to Audio Amp section
- Audio Amplifier
- IC8, IC9 TC4W53FU 8-pin smd 2-Channel Multiplexer/Demultiplexer - Switch between AM or FM distinct high pass filters.
- IC5 CLC2011 8-pin smp 2-channel opamp - Audio pre-amplifier (approx. gain of 5); receives L/R audio from the DSP IC via IC8/IC9 to drive IC7.
- IC7 SP2068EF(APA2068) 16-pin smp 2-channel audio power amplifier - Earphones (2-ch/stereo) and Speaker (bridged mode).
- Q18, Q19 S9014 3-pin smd npn - Enables "DNR2" AGC to control audio low pass filter shape by inserting C59/C57 (22nF) on RC networks at IC5 outputs.
- Line Out
- IC3 CLC2011 8-pin smp 2-channel opamp - Line audio amplifier (approx. gain of 6); receives L/R audio from the DSP IC to drive the Line Out socket.
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