US 12,057,814 B2 · Multiple feedback filter

Abstract

A circuit having an input and an output, the circuit comprising: a first amplifier having a first input, a second input and an output coupled to the output of the circuit; a first capacitor having a first terminal coupled to the first input of the first amplifier and a second terminal coupled to the output of the first amplifier; a first resistor having a first terminal coupled to the first input of the first amplifier and a second terminal; a buffer having an output coupled to the second terminal of the first resistor and an input; a second resistor having a first terminal coupled to the output of the first amplifier and a second terminal coupled to the input of the buffer; a second capacitor coupled between the input of the buffer and ground; and a third resistor coupled between the input of the buffer and the input of the circuit.

Claims11

Dependent claims

A circuit having an input and an output, the circuit comprising:

a first amplifier having a first input, a second input and an output coupled to the output of the circuit;
a first capacitor having a first terminal coupled to the first input of the first amplifier and a second terminal coupled to the output of the first amplifier;
a first resistor having a first terminal coupled to the first input of the first amplifier and a second terminal;
a second amplifier having a first input, a second input and an output, in which the output of the second amplifier is connected only to the second input of the second amplifier and to the second terminal of the first resistor;
a second resistor having a first terminal coupled to the output of the first amplifier and a second terminal coupled to the first input of the second amplifier;
a second capacitor coupled between the first input of the second amplifier and ground;
and
a third resistor coupled between the first input of the second amplifier and the input of the circuit.

5 more elements

A circuit having an input and an output, the circuit comprising:

a first amplifier having a first input, a second input and an output coupled to the output of the circuit;
a first source follower (SF) circuit having an input connected to a reference voltage and an output connected to the second input of the first amplifier;
a first capacitor having a first terminal coupled to the first input of the first amplifier and a second terminal coupled to the output of the first amplifier;
a first resistor having a first terminal coupled to the first input of the first amplifier and a second terminal;
a second SF circuit having an input and an output connected to the second terminal of the first resistor;
a second resistor having a first terminal coupled to the output of the first amplifier and a second terminal coupled to the input of the second SF circuit;
a second capacitor coupled between the input of the second SF circuit and ground;
and
a third resistor coupled between the input of the second SF circuit and the input of the circuit.

6 more elements

Dependencies are inferred from the claim text.

Multiple feedback filter

Life of this patent

Multiple feedback filter

Life of this patent

Abstract

Claims11