In simpler words the IC LM567 IC is a tone decoder chip which is designed basically for recognizing a specified frequency band, and activating the output in response to the detection. Needless to say this chip can be used for a number of different applications, the most common being in the field of remote controls, and security systems.
The important features of LM567 are explained as under:
Highly stable of center frequency, which assures precise passband limits making the unit very reliable with the detection functions.
Independently controllable bandwidth (up to 14%), as the feature suggests, the bandwidth is also adjustable to a reasonable degree.
High out-band signal, and noise rejection, which again assures high reliability during the detection and implementation of the said functions.
Inherent immunity to false signals, which ensures that the chip never produces false results due to incorrect frequency detection or in the presence of stray or spurious instantaneous signals.
Frequency adjustment over a 20-to-1 range with an external resistor, this feature again makes the chip highly flexible and dynamic.
The three important Parameters Associated with the IC LM567 may be understood with the following points:
frequency of the in-built current controlled oscillator circuitry in the
absence of an input signal.
above center frequency, within which the presence of an input signal having a threshold voltage of above 20mV causes the output of the IC to become low. This
feature refers to the loop capture range.
output to switch to logic zero in the presence of a relevant input signal
having a threshold voltage above 20mV.
frequencies thresholds of the detection band.