Calculating Padding Capacitors
Padding capacitors are capacitors added to a variable capacitor in order to change the available range of capacitance.
Generally, we need to add two capacitors - one in parallel and another in series. The diagrams below show the two ways of doing this.
| Configuration a) | Configuration b) |
|---|---|
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Each method requires different values of each of the padding capacitors C1 and C2, and has different implications for the current and voltage seen by each of the three capacitors making up the circuit, and hence implications for power handling and sensitity to temperature coefficients etc.
Click the links below to get to the calculator and the mathematical explanation