ACTIVE RC LOW-PASS FILTER Russian patent published in 2019 - IPC H03H11/12 

FIELD: radio engineering; electronics.

SUBSTANCE: invention relates to frequency-selective means and can be used as a single-pass low-pass filter of second order with zero transmission or as a component of a multi-link filter in different devices for generating and processing radioelectronic signals. Filter comprises operational amplifier, to inverting input of which first and second resistors first leads are connected, wherein the second lead of the first resistor is connected to the output of the operational amplifier, which is connected to the output of the active RC-filter, and the non-inverting input of the operational amplifier is connected to the first leads of the third resistor and the first capacitor, second lead of third resistor is connected to first leads of second capacitor and fourth resistor, and to second lead of latter, which is input of active RC-filter, upper arm of input voltage divider is connected, tapping of this divider is connected to the second lead of the first capacitor, characterized by that between the inverting input of the operational amplifier and the common bus an additional resistor is connected, second output of the second resistor is connected directly to the input of the active RC-filter, and the second output of the second capacitor is connected directly to the output of the operational amplifier.

EFFECT: design of an active RC low-pass filter, which realizes a second-order transmission function with transmission zero when using the minimum possible number of operational amplifiers and frequency-setting capacitors and at the same time allowing to minimize voltage of intrinsic electric noise.

1 cl, 1 dwg