Non-Ideal Effects

Abstract

In the third and fourth chapters, the topologies of a low-pass and a band-pass filter have been presented using ideal components. In this chapter the non-ideal effects from using real components will be presented and discussed. Initially, the non-ideal effects due to the switches are described. The distortion of a first-order low-pass SC filter is simulated using different switch configurations, including with the use of clock boost circuits, in order to determine which configuration is better from a distortion point of view. Two clock boost circuits, one of them capable of operating at lower voltages, are presented. A voltage buffer, and a low gain amplifier are described in several configurations; the low and medium frequency small signal models are presented and the respective transfer functions derived; the thermal noise referred to the input is also derived. The chapter ends with some simulation results, showing power dissipation, gain, gain-bandwidth product, THD, and thermal noise for each version of the circuits.