Capacitors | Passive Components | Components Supplier

What Is Capacitors

A capacitor is a fundamental electronic component designed to store and release electrical energy. It consists of two conductive metal plates separated by a non-conductive layer called a dielectric. When voltage is applied, opposite charges accumulate on each plate, creating an electrostatic field that holds the energy until it is needed by the circuit.

Capacitance — the amount of charge a capacitor can store — is measured in Farads (F) and its subdivisions: microfarads (uF), nanofarads (nF), and picofarads (pF). Capacitors rated at 1 Farad or above are known as Supercapacitors. The capacitance value is determined by the surface area of the plates, the distance between them, and the properties of the dielectric material.

In modern electronics, capacitors perform three critical roles: smoothing voltage fluctuations in power supplies, filtering unwanted signals, and coupling or decoupling different circuit stages. Their compact size, wide availability, and versatility make them one of the most essential passive components across every segment of the electronics industry.

Types of Capacitors

Not all capacitors are created equal. Each type uses a different dielectric material and construction, resulting in distinct performance characteristics suited for specific applications. Here is an overview of the most common types:

Ceramic Capacitors (MLCC)

Ceramic capacitors are the most widely used capacitor type in the world. Non-polarized and available in extremely compact packages, Multilayer Ceramic Capacitors (MLCCs) stack multiple plate-dielectric layers to deliver high capacitance in a tiny footprint. They offer excellent high-frequency stability and low ESR.

Best for: RF filtering, signal decoupling, timing circuits, telecommunications equipment, and consumer electronics.

Electrolytic Capacitors

Electrolytic capacitors use a liquid or solid electrolyte to achieve very high capacitance values at a low cost. They are polarized — meaning correct polarity installation is critical — but offer unmatched capacitance per unit volume for bulk energy storage and voltage smoothing.

Best for: Power supply filtering, audio amplifiers, motor drives, and industrial equipment where large capacitance is the priority.

Tantalum Capacitors

Tantalum capacitors offer superior reliability and stable capacitance over time in a compact package. Using tantalum oxide as the dielectric, they are polarized and must be handled carefully to avoid overvoltage damage. Their dependability makes them a preferred choice in high-stakes applications.

Best for: Smartphones, wearables, medical devices, military electronics, and any design where reliability in a small footprint is critical.

Film Capacitors

Film capacitors use a thin metallized plastic film as the dielectric, delivering low distortion, high accuracy, and outstanding long-term stability. Non-polarized and suitable for both AC and DC circuits, their low ESR makes them excellent for precision and high-fidelity applications.

Best for: High-performance audio equipment, precision signal filtering, power factor correction, and solar inverters.

Polymer Capacitors

Polymer capacitors replace the liquid electrolyte of traditional electrolytics with a solid conductive polymer, dramatically lowering ESR and improving reliability. They resist drying out, withstand harsh environments, and maintain excellent performance at high frequencies — making them a cornerstone of modern high-efficiency designs.

Best for: Electric vehicle power electronics, servers and data centers, industrial automation, and high-speed computing.

Supercapacitors (Ultracapacitors)

Supercapacitors bridge the gap between conventional capacitors and batteries. Using activated carbon to maximize surface area, they store far more energy than standard capacitors and charge/discharge extremely fast — ideal wherever rapid power bursts are needed.

Best for: Electric vehicles, renewable energy storage, UPS backup systems, and regenerative braking applications.

Source Capacitors with Confidence from PCBAndAssembly

Selecting the right capacitor — correct type, value, package, and voltage rating — from a verified source is just as important as the design itself. At PCBAndAssembly, we specialize in components sourcing with 14 years of experience and direct relationships with the world’s top authorized manufacturers and agents.

We supply 100% original, brand-new capacitors from leading brands including:

• AVX, KEMET, Murata, TDK, Taiyo Yuden
• Panasonic, Nichicon, Vishay, EPCOS, Cornell Dubilier
• UCC, and many more top-tier manufacturers

Whether you need standard MLCCs in volume, high-capacitance electrolytics, ultra-reliable tantalums, or specialty polymer capacitors, our sourcing team has the network and expertise to fulfill your BOM quickly and accurately — with full traceability on every part.

✔  100% original and new parts — zero counterfeit risk

✔  14 years of components sourcing experience

✔  Strong global supplier network — even for hard-to-find or allocated parts

✔  Serving PCB assembly manufacturers and engineers worldwide

Need Help Finding the Right Capacitor?

Not sure which type fits your circuit? Can’t locate a specific part number? Our experienced sourcing team is ready to help. We work closely with engineers and procurement teams to identify the right component and deliver it with speed and reliability.

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