Charge control of micro-electromechanical device

本发明提供一种微型机电系统(30)，它包括具有可变电容器(46)的微型机电系统(MEMS)器件(34)和开关电路(40)，所述可变电容器(46)由被可变间隙距离48分隔的可移动的第一导电板(42)和固定的第二导电板(44)形成。开关电路配置成接收具有所选电压电平的参考电压并配置成对启动信号作出响应，所述启动信号的持续时间至少等于MEMS器件的电时间常数但比MEMS器件的机械时间常数要短，在所述持续时间内将所选电压电平加到第一和第二导电板上，使具有所需数量的存储电荷累积到可变电容器上，其中，可变间隙距离随存储电荷数量而变。 The present invention provides a micro-electromechanical system (30) comprising a micro-electromechanical system (MEMS) device (34) having a variable capacitor (46) formed by a movable first conductive plate (42) and a fixed second conductive plate (44) separated by a variable gap distance 48, and a switch circuit (40). The switch circuit is configured to receive a reference voltage having a selected voltage level and configured to respond to an enable signal having a duration at least as long as an electrical time constant of the MEMS device, but shorter than a mechanical time constant of the MEMS device, to apply the selected voltage level across the first and second plates for the duration to thereby cause a stored charge having a desired magnitude to accumulate on the variable capacitor, wherein the variable gap distance is a function of the magnitude of the stored charge.