Browsing by Author "Tsai, Tsung-Heng"

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A Fully-Integrated Wireless Bondwire Accelerometer With Closed-loop Readout Architecture
(2015-10-01)
Liao, Yu-Te
;
Huang, Shih-Chieh
;
Cheng, Fu-Yuan
;
Tsai, Tsung-Heng
;
電機資訊學士班
This paper presents a fully-integrated wireless bondwire accelerometer using a closed-loop readout interface that effectively reduces the noise from electrical circuits and long-term frequency drifts. The proposed accelerometer was fabricated using 0.18-mu m CMOS technology without micro electromechanical systems (MEMS) processing. To reduce manufacturing errors, the bondwire inertial sensors are wire-bonded on the chip pads, thereby enabling a precisely-defined length and space between sensing bondwires. The proposed wireless accelerometer using a pair of 15.2 mu m and 25.4 mu m bondwires achieves a linear transducer gain of 33 mV/g, bandwidth of 5 kHz, a noise floor of 700 mu g/root Hz, and 4.5 mu g bias stability. The acceleration data is digitalized by an energy-efficient 10-bit SAR ADC and then wirelessly transmitted in real time to the external reader by a low-power on-off shift keying (OOK) transmitter. The proposed architecture consumes 9 mW and the chip area is 2 mm x 2.4 mm.
A Low-Power Wireless Bondwire Inertial Sensor System
(2015)
Huang, Shih-Chieh
;
Lu, Shao-Yung
;
Cheng, Fu-Yuan
;
Tsai, Tsung-Heng
;
Liao, Yu-Te
This paper presents the design and implementation of a fully-integrated CMOS accelerometer using bondwires as sensing devices without Micro Electro-Mechanical Systems (MEMS) processes. The model and analysis of bondwire inertial sensors are provided for further implementation of low-power and low-noise accelerometers. Finite element method (FEM) simulation is performed to verify the concept and model. This paper also proposes a closed-loop readout interface that suppresses the in-band noise and reduces both design complexity and power consumption. The bondwire accelerometer is fabricated in a 0.18 mu m CMOS process, achieves a 33 mV/g linear transducer gain within a 5 kHz bandwidth, and consumes 9 mW.
HIGH-SENSITIVITY CMUT WITH INTERLAYER METAL ARCHITECTURE FOR MEDICAL ULTRASONIC SYSTEMS
(2015)
Cheng, Teng-Chuan
;
Liao, Yu-Te
;
Tsai, Tsung-Heng
;
電機學院
;
College of Electrical and Computer Engineering
This paper presents an integration of the capacitive micromachined ultrasonic transducers (CMUTs) and the transimpedance amplifier in medical ultrasound systems. The proposed CMUT and the sensing circuits are both fabricated on the same chip in a 0.18 mu m CMOS MEMS technology. Two interlayer metal structures are proposed to improve the sensitivity. The CMUTs are designed with 2MHz cells for medical diagnosis. The conversion efficiency of the CMUTs is 4 times and 1.8 times higher than that in the published structures.