What are Capacitors and Their Types?

A passive component similar to resistors and inductors, capacitors are essential in every electronic device or electric circuit. Manufactured in numerous forms, styles, lengths, girths, and materials, each capacitor comes equipped with at least two electrical conductors known as plates. Commonly referred to as the dielectric layer, capacitors are also paired with a non-conductive insulating layer which can be polarized by an applied electric field. Designed to be discrete, capacitors are diverse components in account for their range when working with different types of capacitance values, working voltage, current handling capacities, and other related properties.

While capacitors are divided into two main mechanical groups, fixed capacitors and variable capacitors, fixed capacitors are those predominantly used for their fixed capacitance values. As fixed capacitors are primarily named after the type of dielectric inhabiting their structure, it is imperative that capacitors are chosen based on specific current recommendations of electronic equipment. To simplify the function between capacitor types, we will be going over common styles of fixed capacitors to assist you in finding which parts best suit your application needs.

Ceramic Capacitors

Ceramic capacitors consist of two or more alternating layers of ceramic and metal; the ceramic acts as the dielectric while the metal acts as a source of electrodes. Made from finely ground paraelectric or ferroelectric materials formulated with oxides, ceramic mixtures can be modified to achieve a capacitor's desired characteristics.

Film Capacitors

Commonly referred to as a plastic film capacitor, film capacitors are constructed with an insulating plastic film as the dielectric. However, there are various film capacitor configurations available which can employ alternate materials to achieve different capacitance values. Readily accessible and considered to be one of the most abundantly used capacitors, film capacitors are widely used in electronics, in addition to AC and DC electronics circuits.

Polymer Capacitors

An electrolytic capacitor (e-cap) incorporating a solid conductive polymer electrolyte, polymer capacitors branch off into four primary categories consisting of: polymer tantalum (Polymer Ta-e-cap), polymer aluminum (Polymer Al-e-cap), and polymer niobium electrolytic capacitors, alongside hybrid polymer capacitors (Hybrid polymer Al-e-caps). Coming in surface-mount and chip style varieties, capacitors of this classification are known for their low internal equivalent series resistances (ESR) and high ripple current ratings. Mainly used as buffer, bypass, and coupling capacitors among electronic circuits in power supplies, polymer capacitors should be considered where space is limited such as in flat or compact equipment designs.

Aluminum Capacitors

Utilizing aluminum foil as their anode and cathode, aluminum capacitors are polarized electrolytic capacitors similar to polymer capacitors. Forming thin insulating layers of aluminum oxide through the means of anodization, these layers serve as the cathode’s dielectric. Available in three seperate subfamilies of non-solid, solid manganese dioxide, and solid polymer aluminum electrolytic capacitors, aluminum electrolytic capacitors are easily obtainable in a wide range of sizes, capacitance, and voltage values. For optimal support, these parts should be used in power supplies, switched-mode power supplies, and DC-DC converters.

Supercapacitors

Supercapaciters house a subcategory of capacitors which include: electric double-layer capacitors (EDLC), pseudocapacitors, and hybrid capacitors. Unlike other capacitors, supercapacitors do not incorporate a solid dielectric. Instead, they make use of two storage principles referred to as double-layer capacitance and pseudocapacitance. As a result, you can find these parts inhabiting systems with high capacitance values, but low voltage limits.

While most applications of capacitors have a typical lifespan of twenty years, there are instances where user error or part malfunction can cause parts to expire prematurely. In the event that you require replacement parts ranging from mica capacitors, dielectric capacitors, polarized capacitors, and other electronic parts, NSN Unlimited is here to streamline and expedite any one of your orders for immediate procurement. Due to our quality control and export compliance, we operate with AS9120B, ISO 9001:2015, and FAA AC 00-56B certification and accreditation, alongside our NO CHINA sourcing pledge. If you would like to request a quote for your comparisons, you can submit an RFQ form as provided on our website. Upon receipt, a dedicated account manager will quickly review and respond with a personalized solution to your needs in just 15 minutes or less, 24/7x365.