Capacitor Types and Markings: Selection Guide
Compare ceramic, electrolytic, tantalum and film capacitors; understand capacitance markings, voltage derating and how to choose the right capacitor type.
Common capacitor types compared
Multilayer ceramic capacitors (MLCC) are small and low-ESR, ideal for decoupling and bypass. Aluminum electrolytics offer high capacitance for bulk energy storage but are polarized. Tantalum capacitors provide stable capacitance in compact packages, while film capacitors excel in high-voltage and audio applications.
Choose dielectric and package from the required capacitance, rated voltage, ripple current, temperature stability and cost target.
Reading capacitance markings
Ceramic capacitors often use a three-digit code identical in logic to resistors: 104 = 100 nF. Electrolytics print capacitance and voltage directly, e.g. 100µF 25V, with a stripe marking the negative lead.
Apply voltage derating: keep the working voltage at roughly 50–70% of rated voltage for ceramics and ≤80% for electrolytics to maximize reliability.
Frequently Asked Questions
104 capacitor equals how many farads?
104 = 100 nF = 0.1 µF.
Can I replace a capacitor with a higher voltage rating?
Yes, using an equal-or-higher voltage rating with the same (or higher) capacitance is generally a safe upgrade, provided the footprint fits.