5.6 Spice Examples

In many cases, especially with complex circuits, not a complete picture of the noise behavior can be produced. Adding to that the possibility to get the circuit properties in the non-noise domain leads to the necessity of using a computer for simultaneous circuit simulation in the DC, AC, noise, and even in the time domain. In that, circuit parameter variations enable recognizing many of the phenomena which would be very difficult to produce by hand analysis. In this chapter LTspiceLTspice was used and netlists were written for all circuits. The very netlist are not shown here to save space (not to mention that these are designers oriented). Note, use netlist instead of drawing schematics, in the authors’ opinion, leads to much more readable (and controllable) circuit descriptions when complex circuits are used, that especially stands when several component models are used in the same circuit description. Nevertheless, when drawing schematic the reader is recommended first to set the drawing and color preferences in order to get an easy to read drawing. That especially stands for the background color, the line color and width, and the font type and size. We advise the use a font type as it is in the report accompanying the simulation. The set of examples was chosen in order to demonstrate the noise behavior of some indicative circuits, while the results demonstrated are illustrative and suggest what is possible and arguably necessary to get from the simulation.