How do you choose a capacitor size?

When considering the capacitor size for a given application, parameters such as voltage, current ripple, temperature, and leakage current must be considered. Capacitor size selection is important, considering the physical size and capacitance aspects, as they affect circuit assembly and the performance variation of the circuit.

What should be considered when selecting a capacitor?

The primary consideration for capacitor selection should be the nominal capacitance value. Knowing the application is important for determining the capacitance value. Either the designer calculates the capacitance or, in an integrated circuit application, the capacitance is recommended in the IC datasheet.

What are the tolerances for resistors & capacitors?

Tolerances for resistors are optimum if you’re using 1%, 5%, and 10%. Tolerances for capacitors work best in 5% and 10% only. Power rating is important to determine because, through this, we can execute damage control and seamless power dissipation with it to a large extent.

How is a capacitor rated?

Usually, capacitors are derated by the following rule of thumb: a capacitor is selected such that its voltage rating is two to three times greater than the expected operating voltage. Derating increases the footprint requirements of the capacitor because, with an increase in working voltage, the physical size of the capacitor also increases.

How much capacitance should a capacitor have?

The price variation between low tolerance and high tolerance capacitors varies considerably. If price is not a major concern, it is recommended to select a capacitor with tolerance under 10%. However, for most of the low power circuits, the tolerances of 10% or 20% are sufficient. How much capacitance do you really get?

What is the difference between a resistor and a capacitor?

There are fewer standard values for capacitors compared to resistors. Generally, capacitors come available only in the E-6 Series of standard values (10, 15, 22, 33, 47, and 68) followed by a specified number of zeros. It may not be possible to have the exact value of desired capacitance in standard E-series.