Design Issues for Low Power Integrated Thermal Flow Sensors\ud with Ultra-Wide Dynamic Range and Low Insertion Loss

摘要

Flow sensors are the key elements in most systems for monitoring and controlling\udfluid flows. With the introduction of MEMS thermal flow sensors, unprecedented\udperformances, such as ultra wide measurement ranges, low power consumptions and\udextreme miniaturization, have been achieved, although several critical issues have still to\udbe solved. In this work, a systematic approach to the design of integrated thermal flow\udsensors, with specification of resolution, dynamic range, power consumption and pressure\udinsertion loss is proposed. All the critical components of the sensors, namely thermal\udmicrostructure, package and read-out interface are examined, showing their impact on the\udsensor performance and indicating effective optimization strategies. The proposed design\udprocedures are supported by experiments performed using a recently developed test chip,\udincluding several different sensing structures and a flexible electronic interface.