以混频器作为信号处理单?? 元的环振式压力传感器

提出了一种新的环振式数字压力传感器，它采用做在硅梁上的MOS环形振荡器作为敏感元件，两个反方向变化的环形振荡器的输出信号通过集成在片内的混频器实现频率相减，分析了环形振荡器的频率特性，以及环形振荡器的谐振频率和压力的关系，分析并设计了压力传感器的环形振荡器电路、混频器电路、物理结构以及制作工艺，并制作了样品，其灵敏度为1．52kHz／kPa。

A Ring Oscillator Pressure Sensor Using Mixer

A novel digital pressure sensor using Ring Oscillators (RO) and mixer is presented. The sensitive unit of this pressure sensor is MOS ring oscillators located on silicon films. There are two different ring oscillators in this accelerometer with the same electrical parameters. The output signal was achieved by subtracting the syntonic frequency of one ring oscillator from that of another. The subtraction was realized by a mixer located on the bulk silicon. The frequency character of MOS ring oscillator and its relationship with acceleration are descriped. The circuits, physical structures and fabrication processes of RO accelerometer are designed. The sensitivity of fabricated device is 1.52 kHz/kPa.