TABLE OF CONTENTS The switched capacitor integrator is a key building block in analog signal-processing circuits. All filter design can be reduced to noninverting and inverting integrators. In this section, we will first examine continuous time integrators to understand the desired performance of switched capacitor integrators. The remainder of the section will discuss switched capacitor integrators and illustrate their frequency response characteristics. The influence of the non-ideal characteristics of the op amp and switches on the performance will be presented. In Section 9.5 we will look at damped switched capacitor integrators or first-order, low-pass circuits.
Noninverting and inverting continuous time integrators using op amps are shown in Fig. 9.3-1. While it is possible to find a noninverting integrator configuration using one op amp, Fig. 9.3-1(a) is used because it is one of the simplest forms of a noninverting integrator. We will characterize the integrators in this section in the frequency domain although we could equally well use the time domain. The ideal transfer function for the noninverting integrator of Fig. 9.3-1(a) is
where ? 1 is called the integrator frequency. ? 1 is equal to 1/ ? 1 and is called the integrator time constant. ? 1 is the frequency where the magnitude of the integrator gain is unity. For the inverting integrator, the ideal transfer function is
Figure 9.3-2 gives the ideal magnitude and phase response of the noninverting and...
