SECOND-ORDER LOW-PASS FILTER ON TWO SWITCHED CAPACITORS Russian patent published in 2024 - IPC H03H19/00 

FIELD: radio engineering.

SUBSTANCE: disclosed is a low-pass filter, the circuit of which includes additional buffer amplifier (14), wherein series-connected first (7) electronic switch, frequency setting resistor (13) and second (8) electronic switch are connected between the output of buffer amplifier (12) and input of additional buffer amplifier (14), second (9) frequency-setting capacitor is connected between input of additional buffer amplifier (14) and common bus of power supplies, output of additional buffer amplifier (14) is connected to common unit of series-connected first (7) electronic switch and frequency setting resistor (13) through first (15) additional electronic switch, and the common unit of frequency setting resistor (13) and second (8) electronic switch is connected to inverting (4) input of differential operational amplifier (3) through second (16) additional electronic switch.

EFFECT: reducing the number of resistors of the frequency-setting circuit and providing the possibility of frequency tuning by changing the resistance of the resistor, as well as the possibility of realizing high quality factor.

1 cl, 7 dwg