Filtering circuit with efficient filtering function

• Main Author: LYU SHUMIN
• Format: Patent
• Language: English
• Published: 20.05.2015
• Subjects: BASIC ELECTRONIC CIRCUITRY; ELECTRICITY; IMPEDANCE NETWORKS, e.g. RESONANT CIRCUITS; RESONATORS

The utility model belongs to the filter circuit technical field and relates to a filtering circuit with an efficient filtering function. The filtering circuit includes an input end J1, an output end J2, an active filtering unit and a passive filtering unit; the active filtering unit includes a triode Q1, a resistor R4, a capacitor C1, a capacitor C4, a resistor R1 and an amplifier U1; the pin 2 of the amplifier U1 is connected with one end of the resistor R1 and one end of the resistor R2; the other end of the resistor R1 is connected with one end of the capacitor C1 and the emitter of the triode Q1; the base of the triode Q1 is connected with one end of the resistor R4 and one end of the capacitor C4; the collector of the triode Q1 is connected with one end of the resistor R4 and the pin 2 of the input end J1; the passive filtering unit comprises a resistor R3, a resistor R2, a capacitor C3 and a capacitor C2; the pin 1 of the input end J1 is connected with one end of the resistor R3; the other end of the capacitor C2 is connected with the pin 1 of the amplifier U1, the other end of the resistor R2 and the output end J2.