M5227 application circuit

It is the application circuit of M5227P . For the graphic equalizer, its control curve is always
represented by the logarithmic frequency axis, and the control curves are required to be the same and the intervals
are equal to ensure that each frequency band is at the maximum boost or
attenuation of the total frequency. The sound curve is relatively uniform. In order to meet
the graphic requirements for the amount rate axis, the center frequency of each control section must
also be selected according to the octave range. At the same time, in order to ensure that the mutual influence between adjacent
control frequency bands is minimal, each frequency band takes
a larger Q value and keeps the same 0
value for each frequency band. This circuit is a five-segment equalizer. The center
frequency of each control segment is selected according to 3 times the range, namely: 108Hz,
343 H, 1.08kHz, 3.43kHz, 10.8kHz,
and the value is 1-5--1.8.
    In the circuit, the resistance values ​​of RGl and RZ determine the maximum boost and attenuation of each frequency band. The larger the resistance, the
greater the boost and attenuation of each frequency band. This circuit uses ±12dB boost and attenuation. According to the technical parameters provided by the manufacturer , RGl and Rca are both selected as 2.7kflo. Since the values ​​are small, in order to improve the input impedance of the circuit, a first- level voltage follower is
added to the input end . Comprehensive frequency response curve controlled by
each frequency band