Hirokazu Yoshizawa for the degree of Doctor of Philosophy in Electrical and Computer

approved: Gabor C. Temes In this thesis, novel design techniques have been proposed for implementing highlinearity SC circuits in a standard digital CMOS process. They use nonlinear MOSFET capacitors instead of linear double-poly capacitors. To reduce their nonlinearities, a bias voltage is applied to keep MOSFET capacitors in their accumulation regions. For further reduction of distortion, two capacitors can be connected in series or in parallel so that a first-order cancellation of the nonlinearity can be achieved. Experimental results demonstrated that the among these techniques series compensation is the most effective for reducing the nonlinearity of MOSFET capacitors. A novel predictive SC amplifier has been proposed for its insensitivity to op-amp imperfections. Experimental results show that the S/THD of the predictive SC amplifier was 10 dB larger than that of the non-predictive one. It was also shown that a predictive circuit was effective for reducing the nonlinearity caused by the op-amp and/or the MOSFET capacitors. It has been demonstrated that a two-stage op-amp with a large output swing can be fabricated in a standard digital CMOS process. The frequency compensation was accomplished using a source follower and a MOSFET capacitor. An SC amplifier using this two-stage op-amp and double-poly capacitors was fabricated, and it exhibited a large linear output range. Redacted for Privacy A MOSFET-only digitally controlled gain/loss circuit was designed and fabricated in a 1.2 f_tm CMOS process. It demonstrated that the series compensation is effective not only for a large output swing in an amplifier, but also for a large input swing in an attenuator. A pipeline D/A converter utilizing MOSFET capacitors was designed as another application of charge processing technique. It consisted of three parts: a V-Q conversion stage, a charge transfer stage, and a Q-V converter. A new switch configuration which enables the series compensation to have a large bias voltage has also been proposed. It was shown that it works well, and it will be helpful for low-voltage operation, too. © Copyright by Hirokazu Yoshizawa May 15, 1997 All Rights Reserved High-Linearity Switched-Capacitor Circuits in Digital CMOS Technologies by Hirokazu Yoshizawa A THESIS submitted to Oregon State University in partial fulfillment of the requirements for the degree of Doctor of Philosophy Completed May 15, 1997 Commencement June 1998 Doctor of Philosophy thesis of Hirokazu Yoshizawa presented on May 15, 1997