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A very simple with a compact design FM stereo decoder schematic circuit can be designed using the TDA7388 IC manufactured by ST Microelectronics .
The TDA7338 is a monolithic integrated stereo decoder with noise blanking for FM car radio applications.
With the used BICMOS technique, the 19KHz Notch Filter, the PLL Filter and Phase Filter is realized on the chip with a Switched Capacitor concept.
The TDA7338 stereo decoder contains all necessary functions for processing the MPX signal.
The only external component needed for the PLL is the ceramic resonator for the oscillator which runs at 456kHz.

The pilot detector output is designed as an open collector output, therefore an external pull up resistor is needed. To force the decoder to “MONO” Pin 19 has to be clamped to a voltage below 0.8V.
Selecting VCO-OFF (Pin 7 to GND) the VCO is switched off and the SB and HCC are disabled.
This TDA7338 receiver circuit needs to be powered by a 9 volts DC power supply .

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