Research On CMOS Twodimensional Anemometer Macro Model And Its Measurement And Control Circuit

The thermal wind speed and direction sensor is a flow monitor,which has the advantages of small size,low cost,and simple structure.It has been widely used in various fields,such as aircraft,biosensing,heating,ventilation and air conditioning(HVAC)systems.The main technology to meet the above requirements is to achieve the integration of sensor architecture and interface circuits.The advantage of this method is that it can reduce transmission noise,improve reliability and stability,and reduce costs and expectations at the same time.Based on the CSMC.18 ?m process,this article mainly completed two tasks to realize the integrated hot wind speed sensor.One of them is to facilitate the simulation of the interface circuit and improve the simulation accuracy.Through an in-depth analysis of the hot wind speed sensor components,a model of the hot wind speed sensor is created using Verilog-A language,which can work in constant power control mode and constant temperature difference control mode.Second,a model-based hot air speed sensor element,control circuit,and detection circuit design plan is proposed,including the structure of the constant temperature difference control circuit and the successive approximation analog to digital converter(Successive Approximation Register Analog to Digital Converter,SAR ADC)reading Circuit.Realize the sensor element and circuit and MEMS-IC co-simulation to ensure the reliable and stable operation of the integrated thermal wind speed sensor.The Verilog-A macro model of the thermal wind speed sensor describes the behavioral characteristics of constant power and constant temperature difference heating.The consistency between the simulation results of the macro model and the experimental curve proves the correctness of the macro model.Based on the constant temperature difference control circuit of the thermal wind speed and direction sensor macro model,the temperature adjustment error when the temperature changes is less than 3.5%,and the temperature error under different wind speeds is less than 0.36%.The overall simulation result of the analog-to-digital converter in the detection circuit is that the sampling frequency is 100KS/s,the spurious-free dynamic range is 67.2d B,the measured signal-tonoise ratio of the SAR ADC is 57.9d B,and the effective number of bits is 9.33 bits.,The overall power consumption is less than 3m W.In the thermal temperature difference detection system,the readout error of SAR ADC is less than 4.5m V,which meets the design requirements of CMOS system sensitivity.