Monolithic Integrated Active RC Filter Design

In the thesis, a design method which has advantages of less layout consuming, compatible with CMOS process, easy to be integrated, convenient for adjusting the parameters and steady central frequency is presented. The key issues about the design of monolithic integrated active RC filter are discussed. It includes the discussions of the main method for approximation and deduces the pole-placement algorithm which has been used to facilitate the design; Tow-Thomas circuit is used as the circuit building module not only for multiple usage but also for convenient parameter adjusting; the influences of the DC gain, bandwidth, slew rate and danamic range of the amplifier on the filter performance are discussed. A centeral frequency ranged monolithic active RC filter is designed and validated with simulation. The layout is finally given out. 100 kHz～300kHzIn the design, an innovation method of using Mathematica to calculate and factor the symbolic transfer function of the circuit, which graeatly facilitate the design. The rail-to-rail opamp is bringed forward to be used in the design of filters to get rid of the follower with zero-threshold transistor used as the output stage of the opamp. It not only enhances the dynamic range of the filter but also save power consumption and layout area.Tow-Thomas biquad was used as the core circuit of the filter, so that it can be used as a lowpass, bandpass, or highpass filter in the need of adjusting the off-chip passive components. The influences of the gain bandwidth of the opamp on the parameters such as passband gain, quality factor Q and central frequency of Tow-Thomas filter is discussed. This established the relationship between the transistor level and the top level circuit design and bridges the gap between system and transistor level in monolithic integrated active RC filter design.