Yu-Chung Huang

A Semicylindrical Capacitive Sensor With Interface Circuit Used for Flow Rate Measurement

In this paper, a semicylindrical capacitive sensor with an interface circuit used for flow rate measurement is proposed. The numerical analysis method to calculate the capacitance of the semicylindrical capacitive sensor is analyzed and discussed. The picofarad-range capacitive variation of the semicylindrical capacitive sensor can be detected and converted into voltage variation by the interface circuit. Besides, the interface circuit is compact enough to simplify the circuit complexity and could be easily implemented for flow rate measurement. All the functions of the capacitive sensing method of the semicylindrical capacitive sensor used for flow rate measurement are proved successfully through HSPICE simulation. Measurement results have successfully confirmed the correct functions and performance of the semicylindrical capacitive sensor with an interface circuit used for flow rate measurement, which ranges from 0.136 to 4.746 L/min, on the liquid crystal display panel coating machine

A CMOS Integrated Capacitance-to-Frequency Converter with Digital Compensation Circuit Designed for Sensor Interface Applications

In this work, a capacitive signal conditioner of a CMOS integrated capacitance-to-frequency converter with digital compensation circuit designed for sensor interface applications is newly proposed. The proposed converter has the low cost feature. That is due to that the output signal of the proposed converter is a digitized signal produced without realizing the analog to digital converter. Hence, the hardware cost could be reduced. Besides, the output of the proposed converter is a pulse stream, it could be easily sent over a wide range of transmission media, such as PSN, radio, optical, IR, ultrasonic, and etc. Based upon 0.35 um 2P4M CMOS technology, measurement results have successfully verified the correct functions and performance of the integrated capacitance-to-frequency converter with digital compensation circuit designed for sensor interface applications. The area of this fabricated chip is 940 times 1080 um2 and the power consumption is 6.4 mW. The proposed converter is not only suitable for capacitive measurement systems, but also applications of demanding wide dynamic output frequency range.

A Monolithic CMOS Autocompensated Sensor Transducer for Capacitive Measuring Systems

In this paper, a monolithic complimentary metal-oxide-semiconductor (CMOS) autocompensated sensor transducer for capacitive measuring systems is newly presented. The proposed converter is compact and robust to integrate in capacitive measuring systems. The proposed autocompensated sensor transducer is attractive due to the fact that a digitized signal is produced without realizing the analog-to-digital converter. Hence, the hardware cost could be reduced. Furthermore, the output signal of the proposed transducer is a pulse stream; it could be easily sent over a wide range of transmission media, such as package switch networks (PSNs), radios, and optical, infrared (IR), and ultrasonic media. Another innovation is that the proposed automatic compensation circuits enhance and compensate the linear relation between the variable capacitance of the detected sensor and the output digital frequency over a wide dynamic frequency range. Measurement results have successfully verified the functions and the performance of the proposed autocompensated sensor transducer and confirmed that it is possible to apply it to the air pressure sensor. The area of this chip is 940 times 1080 mum2, and the power consumption is 6.4 mW. The proposed transducer is not only suitable for capacitive measuring systems but also practical for application in the front-end systems of the wireless sensor network.

High-resolution MOS magnetic sensor with thin oxide in standard submicron CMOS process

Abstract In this paper, new results obtained with an NMOS magnetic-field sensor made by an industrial 0.8 μm CMOS process are presented. The major disadvantage of MOS magnetic sensors, a larger noise, can be overcome by the submicron CMOS process with 19 nm gate oxide. The device with W/L= 60 μ m 50 μ m biased at saturation region has a resolution of 150 T (Hz) − 1 2 at 1 kHz and 400 nT (Hz) − 1 2 at 100 Hz, respectively. Even when the device size is scaled down W/L = 6 μ/5 μm, the resolution still has the value of 1.5 μ T (Hz) − 1 2 at 1 kHz. The dependence of sensitivity and current-related sensitivity for various bias conditions is discussed in detail and a simple model to explain these trends is established.

A Low-Cost CMOS Integrated Sensor Transducer Implemented as a Capacitance-to-Frequency Converter for Capacitive Measuring

In this paper, a low-cost CMOS integrated sensor transducer implemented as a capacitance-to-frequency converter for capacitive measuring is newly proposed. The proposed converter is attractive due to that a digitized signal is produced without realizing the analog to digital converter. Hence, the hardware cost could be reduced. Based upon the device parameters of 0.35 mum 2P4M CMOS technology with 3.2 V power supply, all the functions and performance of the proposed converter for capacitive measuring are tested and proven through SPICE simulations. The output frequency range is from 0.5 to 500 kHz under the variable capacitance of the detected sensor ranges from 4 to 24 pF. The area of this fabricated chip is 940 x 1080 mum2 and the simulated power consumption is 5.917 mW. The proposed converter is suitable for capacitive measurement systems, for example, applied in the interfaces of pressure measurement, flow meter, humidity sensing, displacement sensors, etc.

A 14-bit oversampled delta-sigma modulator for silicon condenser microphones

In this paper, a 14-bit oversampled delta-sigma modulator for silicon condenser microphones is newly proposed. The proposed oversampled delta-sigma modulator is attractive due to that the requirements of silicon condenser microphones are successfully matched. Based upon the device parameters of 0.35 μm 2P4M CMOS technology with 3.0 V power supply, all the functions and performance of the proposed delta-sigma modulator for silicon condenser microphones are successfully tested and proven through MATLAB in the behavior simulations and SPICE in the circuit simulations. The area of this fabricated chip is 1327 × 944 μm2 and the simulated power consumption is 5.25 mW. The proposed delta-sigma modulator is suitable for silicon condenser microphones applied on mobile phones, laptops, PDAs, and hearing aids, etc.

A Semi-Cylindrical Capacitive Sensor with Interface Circuit using for Fluidic Measuring

In this paper, a semi-cylindrical capacitive sensor with interface circuit using for fluidic measuring is newly proposed. The numerical analysis method to calculate the capacitance of the semi-cylindrical capacitive sensor is analyzed and discussed. Besides, the interface circuit is compact to simplify the circuit complexity, and could be easily implemented for fluidic measuring. The pF-range capacitive variation of the semi-cylindrical capacitive sensor can he detected and converted into voltage variation by the interface circuit. All the functions of the interface circuit are proved successfully through HSPICE simulation. These simulation results have successfully confirmed the correct functions and performance of the semi-cylindrical capacitive sensor with interface circuit using for fluidic measuring

An Automatic Light Monitoring System with Light-to-Frequency Converter for Flower Planting

In this paper, an automatic light monitoring system with light-to-frequency converter for flower planting is newly proposed. Based on the requirements for flower planting, the proposed light monitoring system is thus analyzed and designed. Besides, the designed light transducer, which is implemented as a light-to-frequency converter, is attractive due to that a digitized signal is produced without realizing the analog to digital converter. Hence, the hardware cost could be reduced. All the functions and performance of the proposed light monitoring system are successfully proven through measurement results. The proposed light monitoring system is rather suitable for the needs in a large flower planting area.

A CMOS phase to digital transducer for optical incremental sensors

In this paper, a CMOS phase to digital transducer for optical incremental sensors is newly proposed. This chip adopts a proposed phase-shift method to easily generate phase shifts of signals by using a resistor chain. Different to PLL-based and ADC-based interpolation, the complexity and hardware cost can be relaxed in this proposed chip. Based upon the device parameters of 0.5 µm 2P2M CMOS technology with 5 V power supply, all the functions and performance of the proposed CMOS phase to digital transducer for optical incremental sensors are successfully tested and proven through measurements. The physical layout including ESD I/O pads is 2010 × 1500 µm2. The proposed chip is suitable for optical incremental sensors.

A CMOS phase to digital converter for optical encoders

In this paper, a CMOS phase to digital converter for optical encoders is newly proposed. This chip adopts a proposed phase-shift method to easily generate phase shifts of signals by using a resistor chain. Different to PLL-based and ADC-based interpolation, the complexity and hardware cost can be relaxed in this proposed chip. Based upon the device parameters of 0.5 μm 2P2M CMOS technology with 5 V power supply, all the functions and performance of the proposed CMOS phase to digital converter for optical encoders are successfully tested and proven through SPICE simulations. The physical layout of interpolation circuits and current to voltage converter are 1000 × 600 μm2 and 850 × 760 μm2, respectively. The proposed chip is suitable for optical encoders.