公开(公告)号：EP0975982B1

公开(公告)日：2007-04-11

申请号：EP99905244.2

申请日：1999-02-19

申请人： TOKYO ELECTRON LIMITED

发明人： MATSUMOTO, Toshiyuki ,  HIROTA, Yoshihiro ,  HARADA, Muneo ,  MIYANO, Takaya

IPC分类号： G01R27/26 ,  G01D5/14

CPC分类号： G01D5/2417 ,  G01D5/24 ,  G01D5/2405 ,  G01H11/06 ,  H04R5/04

摘要： An apparatus for detecting an impedance variable in response to a sensed physical amount of a sensor is provided which comprises an impedance-frequency conversion unit and a counter. The impedance-frequency conversion unit converts the sensor impedance to an oscillation signal a frequency of which corresponds to the sensor impedance. The impedance-frequency conversion unit comprises an impedance-voltage converter for providing a voltage corresponding to the sensor impedance, and a Wien bridge oscillator including an element an impedance of which varies in response to the voltage from the impedance-voltage converter, for generating the oscillation signal. The Wien bridge oscillator is capable of generating a square wave signal as the oscillation signal. The counter counts the number of waves (or wave number) of the oscillation signal in a predetermined time period to output a count value which can be handled as a digital signal.

摘要翻译： 提供了一种用于检测响应于感测的传感器的物理量的阻抗变量的设备，其包括阻抗 - 频率转换单元和计数器。 阻抗频率转换单元将传感器阻抗转换为频率对应于传感器阻抗的振荡信号。 阻抗频率转换单元包括用于提供与传感器阻抗对应的电压的阻抗电压转换器和包括阻抗响应于来自阻抗电压转换器的电压而改变的元件的维恩桥式振荡器， 振荡信号。 维恩桥式振荡器能够产生方波信号作为振荡信号。 该计数器在预定时间周期内对振荡信号的波形（或波数）进行计数，以输出可作为数字信号处理的计数值。