Capacitor Types

Ceramic Capacitors

Ceramic capacitors are among the most widely used capacitors in modern electronics. They are compact, inexpensive, highly reliable and available in both through-hole and surface-mount (SMD) packages. Because of their excellent high-frequency performance, ceramic capacitors are commonly used for decoupling, bypassing, filtering, timing and RF circuits.

What Is a Ceramic Capacitor?

A ceramic capacitor uses a ceramic material as its dielectric. Thin metal electrodes are applied to the ceramic layers, creating a compact component capable of storing electrical energy.

Modern multilayer ceramic capacitors (MLCCs) contain many alternating layers of ceramic dielectric and metal electrodes to achieve high capacitance in a very small package.

Construction

Component	Purpose
Ceramic Dielectric	Stores electrical energy in an electric field.
Metal Electrodes	Conduct electrical charge.
Terminal Leads or SMD End Caps	Provide electrical connection.
Protective Coating	Protects against moisture and mechanical damage.

Types of Ceramic Capacitors

Type	Description
Disc Ceramic	Traditional through-hole capacitor with a ceramic disc.
Multilayer Ceramic (MLCC)	Multiple ceramic layers providing high capacitance in a small package.
High-Voltage Ceramic	Designed for high-voltage applications.
RF Ceramic	Optimised for radio-frequency circuits.

Ceramic Capacitor Classes

Class	Characteristics	Typical Use
Class 1 (C0G/NP0)	Excellent stability, very low losses.	Oscillators, RF and precision circuits.
Class 2 (X7R, X5R)	Higher capacitance with moderate stability.	General-purpose electronics.
Class 3 (Y5V, Z5U)	Very high capacitance but poor stability.	Non-critical applications.

Typical Specifications

Specification	Typical Values
Capacitance	1 pF to 100 µF
Voltage Rating	6.3 V to several kilovolts
Tolerance	±0.1 pF to ±20%
Operating Temperature	-55°C to +125°C (type dependent)
Polarity	Non-polarised

Advantages

Small physical size.
Low cost.
Excellent high-frequency performance.
Very low ESR and ESL.
Long service life.
Available in numerous package sizes.
No polarity requirements.

Disadvantages

Capacitance may change with applied voltage.
Class 2 and Class 3 types have larger temperature variations.
Can crack if subjected to mechanical stress.
Lower energy storage compared with electrolytic capacitors.

Common SMD Package Sizes

Package	Approximate Size (mm)
0201	0.6 × 0.3
0402	1.0 × 0.5
0603	1.6 × 0.8
0805	2.0 × 1.25
1206	3.2 × 1.6
1210	3.2 × 2.5

Applications

Power supply decoupling.
Bypass capacitors.
Noise suppression.
RF circuits.
Oscillators.
Microcontroller power filtering.
Switch-mode power supplies.
Communication equipment.
Audio equipment.
Sensor circuits.

Testing Ceramic Capacitors

Inspect for cracks or physical damage.
Measure capacitance with a capacitance meter.
Check for short circuits using a multimeter.
Use an LCR meter for more accurate measurements.
Replace any capacitor showing physical damage or abnormal readings.

Common Faults

Fault	Possible Cause
Short Circuit	Cracked dielectric.
Reduced Capacitance	Ageing or physical damage.
Open Circuit	Broken termination.
Intermittent Operation	Poor solder joints.

Real-World Examples

Equipment	Typical Use
Arduino	100 nF decoupling capacitor.
ESP32	Power supply bypass capacitor.
Smartphone	Thousands of MLCCs for filtering and decoupling.
Switch-Mode Power Supply	High-frequency filtering.
Audio Amplifier	HF bypass and noise suppression.

Key Points

Ceramic capacitors are among the most common capacitors used in electronics.
They are non-polarised and suitable for AC and DC circuits.
MLCCs provide high capacitance in very small packages.
Class 1 capacitors offer excellent stability, while Class 2 and Class 3 provide higher capacitance.
They are widely used for decoupling, filtering and high-frequency applications.

Next Lesson

Continue by learning about Electrolytic Capacitors, which provide much higher capacitance values and are widely used in power supplies and audio amplifiers.

Next Lesson → Electrolytic Capacitors