Ceramic Capacitors: MLCC, Disc & Safety Types
Ceramic capacitors for PCB, through-hole and specialized circuits
A ceramic capacitor uses a ceramic dielectric between conductive electrodes. This collection includes surface-mount multilayer ceramic capacitors (MLCC), leaded monolithic and disc capacitors, value assortments, high-voltage ceramic variants and products described as Y-class safety capacitors. It also includes an unrelated 0805 resistor listing; that product remains identifiable by its own title and resistance options rather than being described here as a capacitor. The electrical characteristics of a ceramic capacitor are determined by its exact dielectric, capacitance, voltage, geometry and manufacturer-specific part data, not by appearance or a combined marketplace title.
Compare the ceramic families
- SMD MLCC: listings span 0201, 0402, 0603, 0805, 1206, 1210 and larger 1808/1812 packages, in values from pF into µF. Match imperial versus metric size codes, footprint, termination, height, selected capacitance and voltage. A title listing many sizes, values or ratings does not assign every rating to every choice.
- C0G/NP0 versus X7R/X5R: selected small-value C0G/NP0 parts target capacitance stability where needed; selected X7R/X5R MLCC offer other value ranges but effective capacitance can drop under DC bias. Dielectric code alone does not specify tolerance, voltage, bias curve, aging, ESR, microphonics or RF performance. Some combined listings mention C0G and X7R or X5R simultaneously: determine which one applies to the exact variant and verify the part specification.
- Leaded monolithic and disc: radial parts and mixed kits include values encoded by three-digit codes, such as 102 = 1 nF and 104 = 100 nF. Check tolerance, lead pitch, ceramic dielectric, voltage and body clearance. A selection labeled 50 V in one listing does not set the rating for other disc or monolithic products.
- High-voltage ceramic: selected disc and MLCC listings advertise 1 kV, 2 kV, 3 kV or higher options. Confirm the selected voltage, creepage and clearance, DC/AC conditions, pulse behavior, temperature and actual part documentation. Do not infer mains safety approval from a high DC rating.
- Y-class safety candidates: listings using Y1, Y2, X1/Y1 or X1/Y2 wording and 250/400 V options must be verified by their physical safety markings, applicable approval certificates, exact capacitance and class before any line-to-earth use. Conflicting X and Y words in a title do not give every variant both classes; voltage text alone is not certification. Choose the required X or Y class from the equipment safety design, not by capacitance alone.
Selection workflow
- Identify circuit role: decoupling, timing, filtering, RF, pulse, high-voltage or certified mains interference suppression.
- Choose the selected capacitance and tolerance in pF, nF or µF; decode markings carefully, then identify C0G/NP0, X7R, X5R or another verified dielectric.
- Compare working voltage and expected bias. For class-II MLCC, check effective capacitance at operating voltage rather than assuming nominal µF remains constant.
- Match SMD footprint and assembly process, or lead pitch, disc diameter and clearance for through-hole parts. Confirm pack quantity separately.
- For line-connected applications, verify approved X/Y classification, voltage, certificates, spacing and equipment design; never substitute a generic high-voltage ceramic part.
Procurement checklist
- Exact part number and selected variant, capacitance code and unit
- Dielectric, tolerance and operating temperature characteristics
- Rated DC or AC voltage, DC-bias curve and pulse data as relevant
- Imperial/metric package dimensions or lead pitch and body size
- Verified safety classification and approval for mains applications
- Pack size and traceable manufacturer source where required
Frequently asked questions
Is a 10 µF 0805 X5R the same as a 10 µF 0805 X7R?
No. Compare the exact parts' temperature range, DC-bias behavior, voltage rating, tolerance, dimensions and application requirements.
Does “104” mean 104 pF?
No. Under the standard three-digit capacitor code, 104 is 100,000 pF, or 100 nF (0.1 µF). Verify unusual seller labels against the actual component.
Can a 2 kV ceramic replace a Y2 capacitor?
Not by voltage alone. A line-to-earth part must carry the required verified safety classification and approvals.
Does “original” in a product title verify the claimed maker?
No. Verify manufacturer part number, markings and sourcing independently when authenticity matters.
