SALLEN-KI CLASS REJECTOR FILTER Russian patent published in 2022 - IPC H03H11/12 

FIELD: radio engineering.

SUBSTANCE: invention relates to the field of radio engineering and can be used to suppress unwanted interference in the processing of sensor signals in automation systems and measuring equipment. Sallen-Key notch filter contains input (1) and output (2) of the device, first (3) and second (4) frequency-setting capacitors, first (5), second (6), third (7) and fourth 8 frequency-setting resistors, the first (9) and second (10) voltage followers. An additional voltage follower (11) and an additional resistor (12) are introduced into the circuit; the common node of which is connected to the input of the second (10) voltage follower, the output of the second (10) voltage follower is connected to the input of the additional voltage follower (11) through the third (7) and second (6) frequency-setting resistors connected in series, the common node of which is connected to the output of the additional voltage follower (11) through the second (4) frequency setting capacitor, and the input of the additional voltage follower (11) is connected to the input of the first (9) voltage follower through the first (3) frequency setting capacitor.

EFFECT: creation of conditions under which the notch filter of the Sallen-Key family is implemented, with the possibility of independent adjustment of the pole frequency and the quality factor of the pole with different resistors exclusively on non-inverting voltage followers.

1 cl, 4 dwg