Realizations of Oscillators and Filters Employing CMOS CDTAs and OTRAs

• Main Authors: Tein-shung Lo, 羅天翔
• Other Authors: Pang-jung Liu
• Format: Others
• Language: zh-TW
• Published: 2011
• Online Access: http://ndltd.ncl.edu.tw/handle/s6mkcc

碩士 === 國立臺灣科技大學 === 電子工程系 === 99 === The research of this thesis is using current-mode active elements to realize universal filters and sinusoidal oscillators. Compared with voltage-mode circuits by using voltage as variables to control circuits, current-mode circuits can get wider bandwidth, higher slew rate, larger dynamic range, better linearity, lower complication and lower power consumption. There are two current-mode active elements designed in this thesis, Operational Transresistance Amplifier (OTRA) and Current Differerncing Transconductance Amplifier (CDTA). OTRA is a current-input, voltage-output active element, and used to realize current-mode universal filter, current-mode quadrature oscillator and voltage-mode sinusoidal oscillator. CDTA is a current-input, current -output active element, and used to realize current-mode universal filter and current-mode quadrature oscillator. Furthermore, we can change the transconductance of CDTA by modulating the bias current to make the circuit electronic-tunable. The chips of CDTA and OTRA are implemented in TSMC 0.35µm CMOS process.