Capacitive Sensing Techniques

There are several approaches to measuring capacitance

• Oscillator based: Usually the frequency of oscillation is proportional to the inverse of some time constant ($f_{osc}\propto \frac{1}{\tau }$) or proportional to the square root of some $LC$ such that $f_{osc}\propto \frac{1}{\sqrt{LC}}$
• Charge-based
• Wheatstone bridge (AC)