Robust Capacitive Measurement System

专利名称：Robust Capacitive Measurement System发明人：Laurent Lamesch申请号：US13701202申请日：20110608

公开号：US20130176039A1公开日：20130711

专利附图：

摘要：A capacitive sensing circuit is disclosed, wherein the transimpedance amplifier infront of the mixer in prior art is removed respectively replaced by an amplifier with lowgain and consequently high dynamic range. The mixer DC offset voltage or currenttogether with the large amplification factor required after the mixer now would result in

an inacceptable DC offset at the output of the signal chain. In order to eliminate theeffect of the mixer offset, the amplifying stages after the mixer are AC coupled to themixer output and one of the signals entering the mixer is phase modulated or amplitudemodulated with a known low frequency signal. An additional mixer after the AC coupledamplifying stages is driven with the same low frequency modulating signal, resulting inthe wanted DC output signal responsive to the capacitance to be measured.

申请人：Laurent Lamesch

地址：Reichlange LU

国籍：LU

更多信息请下载全文后查看