2026-06-18 Ceramic Disc Capacitor Guide: Types, Codes and Applications
A ceramic disc capacitor is a compact electronic
component made from a ceramic dielectric with metal electrodes and
radial leads. It is commonly used for filtering, coupling, bypassing,
noise suppression and high-voltage applications.
checking capacitance, voltage rating, tolerance, dielectric type,
temperature characteristics, lead spacing and safety certification.
For AC mains circuits, only use capacitors specifically approved for
the required safety class.
What Is a Ceramic Disc Capacitor?
A ceramic disc capacitor consists of a disc-shaped ceramic dielectric
coated with conductive electrodes. Radial leads are attached to the
electrodes, and the component is normally covered with a protective
resin or epoxy coating.
Ceramic materials offer good insulation and allow manufacturers to
produce capacitors in a wide range of capacitance and voltage ratings.
Their simple construction, compact size and cost efficiency make ceramic
disc capacitors useful in consumer electronics, industrial automation,
power supplies and power electronics equipment.
However, ceramic disc capacitors are not all interchangeable. Different
dielectric materials can have very different capacitance stability,
temperature behavior and voltage characteristics.
Common Types of Ceramic Disc Capacitors
| Capacitor type | Main characteristics | Typical applications |
|---|---|---|
| General-purpose ceramic disc capacitor | Compact, economical and available in many capacitance values | Filtering, bypassing, coupling and general electronic circuits |
| High-voltage ceramic disc capacitor | Designed for higher DC or pulse voltage | Power supplies, ignition circuits, inverters and test equipment |
| Class 1 ceramic capacitor | High stability and relatively low dielectric loss | Timing, oscillation, RF and precision circuits |
| Class 2 ceramic capacitor | Higher capacitance in a smaller physical size | Bypassing, decoupling and general filtering |
| Safety-certified ceramic capacitor | Designed and certified for defined interference-suppression applications | AC input filtering and isolation-related circuits |
| Automotive or industrial-grade capacitor | Specified for demanding temperature or reliability conditions | Industrial controls, chargers, automotive and outdoor equipment |
How to Read Ceramic Capacitor Codes
Many ceramic disc capacitors use a three-digit capacitance code. The first
two digits are significant figures, while the third digit represents the
number of zeros added in picofarads.
| Marking | Capacitance | Equivalent value |
|---|---|---|
| 101 | 100 pF | 0.1 nF |
| 102 | 1,000 pF | 1 nF |
| 103 | 10,000 pF | 10 nF or 0.01 µF |
| 104 | 100,000 pF | 100 nF or 0.1 µF |
| 221 | 220 pF | 0.22 nF |
| 472 | 4,700 pF | 4.7 nF |
Additional markings may identify tolerance, rated voltage, dielectric,
temperature characteristics or safety certification. Marking systems vary
between manufacturers, so the current datasheet should always be checked.
Key Ceramic Disc Capacitor Parameters
Capacitance
Capacitance determines how much electrical charge the component can store.
Ceramic disc capacitors are commonly specified in picofarads, nanofarads
or microfarads. The required value depends on the filtering, timing,
coupling or suppression function of the circuit.
Rated Voltage
The capacitor’s voltage rating must exceed the voltage experienced during
normal operation. Transients, switching spikes and abnormal conditions
should also be considered.
A higher voltage rating does not automatically make a capacitor suitable
for direct connection to AC mains. Safety certification is a separate
requirement.
Tolerance
Tolerance indicates the permitted difference between the nominal and
actual capacitance. Precision oscillation and timing circuits may require
tighter tolerance than general bypass or noise-filtering circuits.
Dielectric and Temperature Characteristics
The ceramic dielectric affects capacitance stability, operating
temperature, dielectric loss and voltage behavior. Class 1 dielectrics
generally prioritize stability, while Class 2 dielectrics provide more
capacitance in a smaller size.
Lead Spacing and Dimensions
Confirm the lead spacing, disc diameter, thickness and lead diameter.
Electrically similar components may not fit the same PCB footprint or
satisfy the same clearance requirements.
Insulation and Safety Approval
Capacitors used across or between mains-related conductors require the
correct safety classification and certification. Approval marks, rated AC
voltage, impulse rating and application category must match the design.
with an ordinary ceramic disc capacitor, even when capacitance and voltage
markings appear similar. Incorrect substitution can create shock, fire
and equipment failure risks.
Ceramic Disc Capacitor Applications
Industrial Automation Components
Ceramic capacitors are used in PLC modules, sensors, industrial control
boards and power supplies for decoupling, filtering and noise suppression.
Industrial applications may require extended temperature performance and
resistance to electrical interference.
Servo Drives and Motor Control
Servo drives and motor control systems contain high-speed switching
circuits that can generate electrical noise. Ceramic disc capacitors may
support snubber, filtering and electromagnetic interference suppression
functions when correctly specified.
Solar Inverter Components
Solar inverter circuits use capacitors in auxiliary power supplies,
sensing circuits, control boards and noise-suppression networks. Buyers
should consider voltage transients, temperature, humidity and long-term
operating conditions.
Energy Storage Components
Energy storage systems combine high-voltage power conversion with control
and communication electronics. Ceramic capacitors may be used for
decoupling, isolation-related filtering, sensing and suppression.
EV Charger Components
AC and DC EV chargers require reliable power electronics components.
Ceramic capacitors may be found in control circuits, auxiliary power
supplies, EMI filtering and high-voltage sections.
For charging equipment, component selection must account for operating
voltage, temperature, surge conditions, applicable standards and expected
service life.
How to Select a Ceramic Disc Capacitor
- Confirm the required capacitance and permitted tolerance.
- Identify whether the working voltage is AC, DC or pulsed.
- Calculate sufficient voltage margin for normal and abnormal conditions.
- Select the appropriate dielectric and temperature characteristics.
- Check operating temperature, humidity and environmental requirements.
- Confirm disc diameter, thickness and PCB lead spacing.
- Verify safety approvals when the capacitor is used near AC mains.
- Review lifecycle status and manufacturer availability.
only the starting points. The dielectric, safety class, dimensions,
temperature range and application must also be compared.
Information Needed for BOM Sourcing
| Required information | Why it matters |
|---|---|
| Manufacturer part number | Identifies the original electrical and mechanical specification |
| Capacitance and tolerance | Determines circuit function and permitted variation |
| Rated AC or DC voltage | Prevents selection based on an incorrect voltage type |
| Dielectric or temperature code | Indicates stability under temperature and voltage |
| Safety class | Required for specific mains-connected applications |
| Lead spacing and dimensions | Ensures compatibility with the existing PCB |
| Application | Helps evaluate pulse, frequency and environmental requirements |
| Required quantity | Supports availability checks and accurate quotation |
How EASYIEE Supports Ceramic Capacitor Sourcing
EASYIEE supports OEM component sourcing, BOM procurement and electronic
component matching for industrial automation and power electronics
projects.
- Ceramic disc capacitor and high-voltage capacitor sourcing
- Multi-line BOM matching and quotation
- Manufacturer and part-number matching
- Alternative component searches for obsolete or shortage parts
- Consolidated sourcing for prototypes and production orders
Browse our
electronic components,
view supported
manufacturers
or learn more about our
BOM sourcing services.
Need Ceramic Disc Capacitors for Your BOM?
Send us the manufacturer part number, capacitance, voltage, tolerance,
safety class and required quantity. EASYIEE will help check availability
and suitable sourcing options.
Frequently Asked Questions
Are ceramic disc capacitors polarized?
Most ceramic disc capacitors are non-polarized, so they do not have
positive and negative terminals. The datasheet should still be checked
before installation.
What does 104 mean on a ceramic capacitor?
The code 104 normally represents 100,000 pF, which is equal to 100 nF
or 0.1 µF.
Can I replace a ceramic disc capacitor with a higher voltage rating?
It may be possible, but capacitance, dielectric, tolerance, dimensions,
safety class and circuit behavior must also match. Engineering approval
is recommended.
Can an ordinary ceramic capacitor be used on AC mains?
No. AC mains applications require a capacitor with the correct safety
classification and approvals for the specific circuit position.
Can EASYIEE help source obsolete ceramic capacitors?
Yes. Provide the original part number, technical specifications,
application and quantity. Available alternatives still require customer
testing and final approval.
Technical References
Additional technical and product information is available from
Murata,
TDK and
Vishay.
Always use the latest manufacturer datasheet when approving a component.
