Most Common Capacitor Types

Capacitors are one of the primary components found in all electronic devices, making them vital to their operation. Modern day electronics are usually equipped with ceramic capacitors decoupling power supplies for a majority of integrated circuits (ICs) on circuit boards or aluminum electrolytic capacitors as bulk capacitance for voltage regulators. As capacitors are utilized for reasons other than noise mitigation, there are several different types of capacitors available on the market. For instance, they can be used for coupling, decoupling, as filters, energy storage/supply, impedance matching, snubbers, and more.

While many think that capacitors are a stable technology that has not changed in decades, they have actually changed significantly in the last 20 years. In fact, unconventional applications take advantage of capacitors. However, it is important to note that different types of capacitors provide varying levels of capacitance, but it is not the only factor to consider when selecting a capacitor. For example, you must take capacitance, maximum voltage, equivalent series resistance (ESR), equivalent series inductance (ESL), longevity, size, price, availability, temperature, and other parameters into consideration. Choosing a capacitor generally begins with the constraints of your application. To better understand how to choose the right capacitor for you, we will outline three of the most common types below.

Ceramic Capacitors

Ceramic capacitors serve as the most popular type of capacitors. Multilayer ceramic capacitors (MLCCs) are one example that are used in circuits and have a capacitance rating that can reach hundreds of microfarads (µF). MLCCs have a ceramic dielectric body, which is composed of a mixture of finely ground granules of para-electric or ferroelectric materials and other components. To create the capacitance, there are multiple layers of electrodes. Meanwhile, the ceramic is sintered at high temperatures to form the electrical and mechanical basis of the capacitor. The ceramic layers are typically very thin, but this is primarily determined by the voltage rating of the component. The capacitor is protected from moisture and other contaminants with a thin protective coating. MLCCs are especially popular because they are compact and have relatively high capacitance. Furthermore, they have a wide voltage range, low ESR, and high Q at high frequencies.

Tantalum Capacitors

This is a type of electrolytic capacitor that is made with a tantalum metal as the anode which is encapsulated by a thin layer of oxide that acts as the dielectric. Since tantalum has a thin dielectric layer, it has a higher capacitance value per unit volume. Furthermore, tantalum capacitors are polarized, meaning that they are only compatible with a DC supply. If it is used outside of its rated voltage/temperature or with the incorrect polarity, then fires or small explosions may occur. To prevent this from happening, current limiters or thermal fusers can be utilized. Unfortunately, this makes them more expensive than their counterparts, so their usage is rare.

Aluminum Electrolytic Capacitors

In modern electronics, aluminum electrolytic capacitors find use in bulk capacitance applications where large amounts of capacitance are necessitated due to their bulk, high ESR, and current leakage. While they are not used as often today, they are still popular because of their wide-ranging capacitance values, high maximum voltage ratings, and low cost. In terms of construction, aluminum electrolytic capacitors have liquid electrolytes with a high concentration of ions. On the other hand, they have a very high equivalent series resistance which causes them to dissipate a lot of power when signals with a high frequency or large amplitude are applied to the capacitor. More than that, aluminum electrolytic capacitors have a limited service life in high temperature environments.

Other common capacitor types include polymer, mica, silicon, and supercapacitors.

Conclusion

Alpha Purchasing is a leading supplier of capacitors, all of which have been sourced from top global manufacturers that we trust. With countless ready-to-purchase options, get started by requesting a quote on any item that sparks your interest. For questions about our other offered services, call or email us at any time; we are available 24/7x365!