DESIGN OF INTEGRATED THERMAL FLOW SENSORS USING THERMAL SIGMA-DELTA MODULATION

Large-scale use of thermal flow sensors in consumer electronics, medic al and automotive applications is seriously hampered by the limited re sponse speed and the non-standardized format of the output signal of c onventional thermal flow sensors. A thermal sigma-delta-based feedback system can be used to provide an optimal interface for a wide variety of new as well as existing thermal flow sensors. Advantages of this s ystem are an improved response time of the sensor system and an inhere nt analog-to-digital conversion of the measurement signal. Realized se nsor implementations range from sensors for flow control in consumer e lectronics, respiration control, to industrial mass-flow control.