Stray Capacitance in Throttle Controller PCB Board Design

Stray Capacitance in Throttle Controller PCB Board Design

When two conductors aren’t short-circuited together, or totally screened from each other by a conducting (Faraday) screen, there is a capacitance between them. So, on any Throttle Controller PCB Board design, there will be a large number of capacitors associated with any circuit (which may or may not be considered in models of the circuit).

Where high frequency performance matters (and even dc and VLF circuits may use devices with high Ft and therefore be vulnerable to HF instability), it is very important to consider the effects of this stray capacitance.

Any basic textbook will provide formulas for the capacitance of parallel wires and other geometric configurations (see References 9 and 10). The example we need consider in this discussion is the parallel plate capacitor, often formed by conductors on opposite sides of a Throttle Controller PCB Board. The basic diagram describing this capacitance is shown in below Figure.

Capacitance of two parallel plates