on December 1th 18,562

Ceramic Capacitors: Types, Structure, Codes, Performance, and Applications

Ceramic capacitors are components you use to store and control electrical energy in a circuit. In this article, you’ll learn what they are, how they’re built, and the different types you’ll commonly work with. You’ll also see how to read capacitor codes, what affects their performance, and how they compare to other capacitor types. By understanding these basics, you’ll be able to choose the right ceramic capacitor for your projects and applications.

Catalog

Figure 1. Ceramic Capacitors

What are Ceramic Capacitors?

A ceramic capacitor is a fixed-value capacitor that uses a ceramic dielectric to store and release electrical energy. It stabilizes voltage, filters signals, blocks DC, and smooths power in a wide range of electronic circuits. They are widely used because they offer high reliability, low cost, compact SMD packages, low equivalent series resistance (ESR), and excellent high-frequency performance. Ceramic capacitors appear in consumer electronics, automotive systems, power management modules, and communication devices.

Figure 2. Structure of a Ceramic Capacitor

Types of Ceramic Capacitors

There are four main types of ceramic capacitors, each built for a specific purpose. The sections below explain what each type does and where it is used.

Multilayer Ceramic Capacitor (MLCC)

Figure 3. MLCCs

Multilayer Ceramic Capacitors (MLCCs) are compact, surface-mount components made from stacked ceramic dielectric layers and metal electrodes. This design allows MLCCs to achieve high capacitance in a small package, making them widely used in smartphones, computers, and automotive electronics. Compared to other ceramic capacitor types, MLCCs offer excellent frequency performance, low ESR, and strong reliability for high-density circuits. Their versatility, low cost, and wide range of capacitance values make them the most common ceramic capacitor used in modern electronic devices.

Ceramic Disc Capacitor

Figure 4. Ceramic Disc Capacitors

Ceramic Disc Capacitors are traditional radial-leaded components with a flat, circular ceramic body often used in low-cost filtering and bypass applications. Their simple disc structure makes them easy to identify and suitable for through-hole circuit designs. Unlike MLCCs, which are optimized for compact SMD layouts, ceramic disc capacitors handle higher voltages and provide stable performance in general-purpose circuits. They remain a popular choice for power supplies, consumer electronics, and basic timing applications due to their durability and affordability.

Feedthrough Ceramic Capacitor (FCC)

Figure 5. Feedthrough Ceramic Capacitors

Feedthrough Ceramic Capacitors (FCCs) are specialized components designed to filter high-frequency noise as signals pass through a grounded barrier. Their unique feedthrough structure provides superior EMI/RFI suppression compared to standard ceramic capacitors. FCCs are commonly used in communication equipment, RF circuits, shielding panels, and sensitive electronic systems that require strong noise filtering. Unlike MLCCs and ceramic disc capacitors, FCCs are engineered specifically for noise isolation rather than general circuit capacitance.

Ceramic Power Capacitor (CPC)

Figure 6. Ceramic Power Capacitor

Ceramic Power Capacitors (CPCs), also known as doorknob capacitors, are high-voltage ceramic capacitors built for RF power, pulse circuits, and industrial applications. Their thick ceramic dielectric and robust metal housing allow them to withstand extremely high voltage and high current conditions. Compared to MLCCs and ceramic disc types, CPCs offer far greater power handling but come in much larger physical sizes. These capacitors are commonly used in radio transmitters, capacitor banks, high-voltage power supplies, and other applications requiring maximum energy stability and durability.

Ceramic Capacitor Codes and Value Conversion

Figure 7. Ceramic Capacitor Value and Code Conversion Chart

The figure above shows a conversion chart for ceramic capacitor values, listing capacitance in picofarads (pF), nanofarads (nF), and microfarads (µF) along with their corresponding 3-digit capacitor codes.

Ceramic Capacitor Performance Factors

Several operating conditions can influence the actual capacitance, stability, and long-term reliability of ceramic capacitors. Understanding these factors helps ensure proper component selection and better circuit performance.

Temperature

Temperature changes have a strong impact on Class II dielectrics such as X5R and X7R, causing noticeable capacitance variation across their operating range. In contrast, Class I dielectrics like NP0/C0G remain extremely stable and maintain their capacitance even under wide temperature shifts.

DC Bias Effect

When a ceramic capacitor operates near its rated voltage, its capacitance can decrease. This effect is most common in high-K dielectrics such as X5R and X7R, where applying a higher DC voltage can reduce usable capacitance.

Frequency

At higher frequencies, dielectric losses increase, causing a drop in effective capacitance. This makes frequency behavior an important consideration for RF circuits, high-speed digital systems, and switching power supplies.

Aging

Class II ceramic capacitors naturally lose capacitance over time in a predictable, logarithmic pattern, typically 1–7% per decade of hours. Class I capacitors do not exhibit this aging effect.

Mechanical Stress

Multilayer ceramic capacitors (MLCCs) are susceptible to flex cracking caused by PCB bending, vibration, or improper mounting. These cracks can lead to performance loss or complete failure.

Humidity and Environmental Conditions

High humidity or exposure to harsh environments can lower insulation resistance and increase leakage current, reducing overall reliability. Proper coating or encapsulation helps mitigate these risks.

Ceramic vs. Electrolytic vs. Tantalum

Ceramic, electrolytic, and tantalum capacitors behave differently in circuits. The table below compares their key differences.

Aspect	Ceramic Capacitor	Electrolytic Capacitor	Tantalum Capacitor
Dielectric Material	Ceramic layers	Aluminum oxide + electrolyte	Tantalum pentoxide + electrolyte
Polarity	Non-polar	Polarized	Polarized
Capacitance Range	Very small to medium (1 pF–100 µF)	High (1 µF–10,000 µF)	Medium (0.1 µF–1,000 µF)
Voltage Rating	Wide range (6.3V–3kV)	Medium (6.3V–450V)	Lower to medium (2.5V–50V)
ESR (Equivalent Series Resistance)	Very low ESR	High ESR	Low to medium ESR
ESL (Equivalent Series Inductance)	Very low ESL	Medium ESL	Low ESL
Frequency Performance	Excellent for high frequency	Poor for high frequency	Good for mid-frequency
Stability	Class I: very stable; Class II: moderate	Not stable over temperature	Stable compared to electrolytic
DC Bias Effect	Noticeable on X5R/X7R	Minimal	Minimal
Aging Behavior	Class II loses capacitance over time	Degrades gradually with use	Very stable aging
Leakage Current	Very low	High	Low
Ripple Current Handling	Good	Very good for large ripple	Moderate
Physical Size	Very small MLCC packages	Larger size	Small and compact
Failure Mode	Cracks due to flex stress	Dry-out, increase ESR	Can fail short if overstressed

Advantages and Disadvantages of Ceramic Capacitors

Advantages

• Very low ESR and ESL

• Excellent high-frequency characteristics

• Wide voltage range (6.3V–3kV)

• Compact MLCC sizes for SMD use

• Affordable and widely available

• Long service life with high reliability

Disadvantages

• Capacitance derates under DC bias

• Aging in Class II dielectrics

• Mechanical cracking due to stress or flex

• Limited capacitance compared to electrolytics

Applications for Ceramic Capacitors

Ceramic capacitors are used across nearly all modern electronics due to their versatility and performance.

Decoupling and Bypass

Ceramic capacitors are commonly placed near ICs to reduce electrical noise. They help maintain a steady voltage by filtering sudden fluctuations on power lines. This ensures stable operation of digital and analog components.

Power Supply Filtering

These capacitors provide high-frequency filtering in switching power supplies and regulators. They remove unwanted ripple and electrical noise from the output voltage. This results in cleaner and more stable power delivery to sensitive circuits.

RF and Communication Circuits

Ceramic capacitors are used in RF circuits for tuning and precise filtering. They support impedance matching to ensure maximum signal transfer between components. Their low losses make them suitable for high-frequency communication systems.

Timing and Oscillator Circuits

Class I ceramic capacitors offer excellent stability for timing-related functions. They maintain consistent capacitance over temperature and time. This makes them ideal for oscillators, clocks, and frequency control circuits.

Automotive Electronics

MLCCs are widely used in automotive systems because they can tolerate high temperatures and harsh environments. They withstand vibration, shock, and mechanical stress found in vehicles. These qualities make them reliable for ECUs, sensors, and control modules.

Industrial Equipment

Ceramic capacitors are used in motor drives, automation systems, and industrial controls. They support stable performance in environments with electrical noise and temperature variations. Their durability makes them suitable for long-term industrial operation.

Conclusion

Ceramic capacitors help stabilize voltage, filter signals, and work well at high frequencies in many electronic systems. Their design and material allow them to be used in everything from small gadgets to automotive and industrial equipment. Factors like temperature, DC bias, frequency, aging, and environment affect how well they perform. With their small size, low cost, and strong reliability, ceramic capacitors remain one of the most widely used components in electronics.