Figure shows the circuit diagram of Single chip FM Radio circuit. This circuit is based on the monolithic IC TDA 7000 which is the central part of this circuit. This IC TDA 7000 contains a Frequency-Locked-Loop system having an intermediate frequency of 70 KHz. This IC is very much suitable for FM portable radios with minimum peripheral components.
The job of intermediate frequency selection is done by the RC filter of the circuit. Some alignment is needed in the resonant circuit for the oscillator. This is for selecting the reception frequency. A special circuit called mute circuit employed here to avoid spurious reception. This circuit is also helpful to eliminate noise in the input signal. IC TDA 7000 can withstand up to 10 V supply voltage. But here 6V DC supply is used for powering the circuit. An 8 Ohm speaker or headphone can be used at the audio output of this circuit.
- Use a good quality PCB to assemble this circuit.
- The circuit given here is designed as per the data sheet.
- Special steps are taken for this circuit to meet the radiation requirements.
- Use a 50mm long insulated copper wire for antenna.