KR970077968A - DC offset elimination circuit - Google Patents

Abstract

The present invention relates to a DC offset removing circuit, and more particularly, to a DC offset removing circuit using an OP amplifier.

A DC offset canceling circuit according to the present invention is characterized in that a signal source including a first resistor and a DC component is connected in series to a negative input terminal of a first operational amplifier and a second positive input is connected between the negative input terminal and an output terminal of the first operational amplifier A differential amplifying unit connecting a resistor and connecting a voltage source of a DC component of the signal source and a third resistor in series to a positive input terminal of the first OP amplifier and connecting a fourth resistor between the positive input terminal and the ground; And an inverting amplifier for inverting the output of the differential amplifier to an original phase and controlling the amplification to output the same as the AC level of the signal source. As described above, the offset eliminating circuit according to the present invention eliminates the setting time by the conventional coupling capacitor and prevents the level or phase fluctuation according to the frequency change of the AC signal source.

Description

DC offset elimination circuit

Since this is a trivial issue, I did not include the contents of the text.

FIG. 1 is a circuit diagram of one embodiment for removing a DC offset in accordance with the present invention. 2 is a circuit diagram of another embodiment for eliminating the DC offset according to the present invention.

Claims (3)

A DC offset removing circuit comprising: a first resistor connected in series with a first resistor and a signal source including a DC component to a negative input terminal of the first operational amplifier; and a second resistor between the negative input terminal and the output terminal of the first operational amplifier A differential amplification unit connected to a positive input terminal of the first OP amplifier in series between a voltage source and a third resistor of a DC component of the signal source and connecting a fourth resistor between the positive input terminal and the ground; And an inverting amplifier for inverting the output of the differential amplifier to an original phase and controlling the amplification to output the same as the AC level of the signal source. 2. The DC offset removal circuit of claim 1, wherein the first resistance and the second resistance ratio are the same as the third resistance and the fourth resistance ratio. A circuit for inverting each other and for inputting a signal having a DC offset to remove a DC offset, comprising: a first signal source including a first resistor and a DC component connected in series to a negative input terminal of a first operational amplifier, And a third resistor connected in series between the voltage source of the DC component of the first signal source and the positive input terminal of the first OP amplifier, A differential amplifying part connecting a ground to a fourth resistor; A second signal source having the same structure as that of the first differential amplifier and inverted in phase with the first signal source is connected to the negative input terminal side of the second OP amplifier and the offset signal of the second signal source is connected to the second A second differential amplifier connected to the positive input terminal of the operational amplifier; And a third differential amplifying unit for receiving the output of the first differential amplifying unit and the second differential amplifying unit and amplifying the difference between the inverted signals of the first signal source and the second signal source, . ※ Note: It is disclosed by the contents of the first application.