RC integrating circuit

Abstract

The invention discloses an RC integrating circuit, wherein an MOS transistor is added in a feedback loop of the RC integrating circuit which is applied to an active-power filtering circuit so that the added MOS transistor and an integrating capacitor Ci form a zero pole; the generated zero pole of the MOS transistor and the Ci just counteracts a parasitic pole caused by an RC integrator in the active-power filtering circuit by controlling the resistance value of the MOS transistor, therefore, the generation of peak response is avoided, and the linear characteristics of an active-power filter are further kept; and meanwhile, the RC integrating circuit is also additionally provided with a tracking circuit in order to guarantee the zero-pole counteraction effect under the condition of environmental changes, and the tracking circuit self-adaptively controls the resistance value of the MOS transistor according to parameter changes of components in the RC integrating circuit, thereby ensuring that the zero-pole counteraction effect is not influenced by environmental changes.

Description

technical field [0001] The invention relates to an RC integrating circuit, in particular to an RC integrating circuit capable of eliminating the peak response of the active filter where it is located. Background technique [0002] Fig. 1(a) shows a seventh-order active filter, and the RC integrators in the active filter are all fully differential RC integrators. Figure 1(b) shows a fully differential RC integrator commonly used in the active filter shown in Figure 1(a). In order to facilitate circuit analysis, the following is combined with the fully differential RC integrator shown in Figure 1(c) The equivalent half circuit of the RC integrator is described. As shown in FIG. 1( c ), the RC integrator includes a transconductance operational amplifier OPA (Operational Amplifier), a resistor R2 , an integrating capacitor Ci and a biasing circuit. [0003] Wherein, the OPA includes an input terminal, an output terminal and a bias terminal. The input signal Vi is connected to...

AI Technical Summary

Problems solved by technology

However, when the frequency of the input signal of the active filter reaches the edge of the pass band of the active filter circuit, a peak response (Peaking Response) will occur, that is, a large output voltage will appear

Images