A CMOS Integrated Flow Sensor with Output Modulated by Pulse-Width
具有脉宽调制输出的CMOS集成流量传感器

A CMOS integrated flow sensor with digital output has been introduced. The sensor consistsof a temperature sensing stage, a heating stage and a Schmitt trigger. The circuits are connectedto make the sensor work at the oscillation state of heating and cooling, producing a squarewave output.The pulse width of the square wave is used as a measure of flow velocity. Thesensor is fabricated by the conventional CMOS process.