A single IC as illustrated in the figure, consist of almost all the active components that an AM receiver constitutes in general cases. However the resonant networks required for the circuit operation, needed to be supplied externally. RF converter, IF amplifier, detector and AGC circuit, a built-in regulator zener diode, and the audio preamplifier stage are the crucial portion of the IC. We can also see in particular AM receiver system ICs, the RF amplifier is included and the tuning meter/ pre-amplifier is omitted completely from the system.
Few parameters stated below describe and represent the system in more proper way:-
- Sensitivity– The sensitivity of the entire AM receiver system is defined by the specific RF and coil arrangement (at 1 MHz), along with 30% AM modulation, at an audio frequency set at 400 Hz in order to generate a specified output voltage level.
For 10 mV output, required sensitivity would be 3.0 µV.
- Signal-to-noise ratio- This parameter compares between desired signal and noise persisting in the surrounding. It is calculated under the similar conditions as stated above.
General value would for SNR is 45 dB.
- Maximum power dissipation- It gives the utmost amount of power loss by the system to the surrounding at the room temperature. The common value of maximum power dissipation for AM receiver system ICs is 600 mW.
Applications of AM Receiver System
-Particularly suited in miniature and subminiature AM receivers of the broadcast, weather and other types.