公开(公告)号：EP2259426A1

公开(公告)日：2010-12-08

申请号：EP10165027.3

申请日：2010-06-04

Applicant: STMicroelectronics S.r.l.

Inventor： Visconti, Andrea ,  Prandi, Luciano ,  Caminada, Carlo ,  Angelini, Paolo

IPC: H03H19/00

CPC classification number: H03H11/126 ,  H03H19/004

Abstract: A band-pass filter made up by an operational amplifier (2) and by an input circuit. The input circuit is formed by a capacitive filtering element (C 1 ), connected to the input of the operational amplifier; a coupling switch (11), coupled between an input node (10) and the capacitive filtering element; a capacitive sampling element (C s ), coupled between the input of the filter and the input node; and a sampling switch (16), coupled between the input node and a reference-potential line. The coupling switch and the input sampling switch close in phase opposition according to a succession of undesired components sampling and sensing steps, so that the capacitive sampling element forms a sampler for sampling the undesired component in the undesired components sampling step, in the absence of the component of interest, and forms a subtractor of the undesired components from the input signal in the sensing step.

Abstract translation: 带通滤波器通过在运算放大器（2），并通过在输入电路组成。 输入电路是由连接到所述运算放大器的输入端的电容滤波元件（C 1）形成的; 一个耦合开关（11），耦合在输入节点（10）和所述电容性过滤元件上之间; 耦合在所述过滤器和所述输入节点的输入端之间的电容采样元件（C S）; 和采样开关（16）耦合在输入节点和基准电位线之间。 耦合开关和所述输入采样开关接近反相雅丁到不期望的组分的采样和感测步骤的连续，所以没有电容采样元件形成一个采样器，用于采样的不希望的组分取样步骤中不希望的成分，在不存在的 感兴趣的组分，并且形成从在所述感测步骤的输入信号中的不期望的组分的一个减法器。