DISCRETE-ANALOGUE SECOND-ORDER FILTER ON SWITCHED CAPACITORS AND SIGNAL ADDER BASED ON MULTIDIFFERENTIAL OPERATIONAL AMPLIFIER Russian patent published in 2024 - IPC H03H19/00 

FIELD: radio engineering.

SUBSTANCE: disclosed is a discrete-analogue filter, the circuit of which includes multidifferential operational amplifier (12), the inverting input of the first port of which is connected to its output, the non-inverting input of the first port is connected to output (2) of the device, inverting input of second port is connected to common bus, and non-inverting input of second port is connected to input (1) of device, output of multi-differential operational amplifier (12) is connected to the input of buffer amplifier (10) through first (7) switch, resistor (11) and second (8) switch, between the input of buffer amplifier (10) and the common bus second (9) capacitor is connected, output of buffer amplifier (10) is connected to common unit of series-connected first (7) switch and resistor (11) through first (13) additional switch, and the common unit of series-connected resistor (11) and second (8) key is connected to inverting (4) input of amplifier (3) through second (14) additional key.

EFFECT: reducing the number of resistors of the frequency-setting circuit and providing the possibility of frequency tuning, as well as implementation of high Q-factor.

1 cl, 7 dwg