Second-Order Oscillator Using OTRAs And Resistors Without Capacitors

• Main Authors: YUAN-JIA LIANG, 梁原嘉
• Other Authors: JYUN-MING JHANG
• Format: Others
• Language: zh-TW
• Published: 2012
• Online Access: http://ndltd.ncl.edu.tw/handle/82410473709770167660

碩士 === 中原大學 === 電機工程研究所 === 100 === Operational Trans-conductance Amplifier (OTA) is recognized as the best active components in the analog circuit design. Operational trans-resistance amplifier (OTRA) has a dual relationship with OTA. There are the potential advantages in the design of circuit, so OTRA is used an active components to design the circuit in this thesis. In the past, designer used to let Rm approach to infinity, but it lead to more inaccuracy. In this thesis, Rm approach to a finite valueRm(s)=Rmo/(1+s/wo)and ,the(s/wo)>>1. Now,Rm(s)=1/s*(1/Rmo*wo) approximate equivalent transfer capacitor. When design circuits, have three emphases: 1.Each equation has to include equal transfer capacitor. 2. In the equation, the other moved to the other side of the equation, except equal transfer capacitor, positive terminal inputs of Circuit are positive. 3. Negative terminal inputs of Circuit are negative. 4. Equation not include (Vi - Vj)G；i≠j. This way lets inaccuracy smaller. According to analytical synthesis method, I will design second-order oscillator by using two OTRAs and three resistors without capacitors. The result simulated and regulated conformed to the result I assumed, and it had the minimum error. Another major contribution in this thesis is to control the amplitude value. When I change the internal ratio of OTRA’s length and width, the equivalent capacitance values were changed. Controlling Vbias let that the equivalent capacitance values were unchanged. Therefore, amplitude value is smaller. The result is entirely correct in accordance with the law of conservation of energy. The circuit was simulated with TSMC 035um process by H-Spice. Controlling output amplitude value is important in this thesis.