Multilayer Ceramic Capacitors (MLCCs) are essential components in modern electronics. This guide covers the key selection criteria for choosing the right MLCC for your application.

Dielectric Selection

The dielectric material determines the capacitor's temperature and voltage characteristics:

  • C0G (NP0) - Class I ceramic with ultra-stable capacitance (0±30ppm/°C). Best for precision timing, RF circuits, and filters. Limited capacitance range (0.5pF to 47nF).
  • X7R - Class II ceramic with ±15% capacitance change over -55°C to +125°C. Good for general-purpose decoupling and filtering. Wide capacitance range (100pF to 47µF).
  • X5R - Class II ceramic with ±15% capacitance change over -55°C to +85°C. Cost-effective for consumer electronics. Capacitance range 1nF to 100µF.

Case Size Selection

Case size affects capacitance density, current capability, and DC bias performance:

  • 0201/0402 - For space-constrained mobile devices
  • 0603/0805 - General purpose, best availability
  • 1206/1210 - Higher capacitance and current capability

Voltage Rating

Always apply voltage derating for reliability:

  • Standard derating - 80% of rated voltage (20% margin)
  • High-reliability - 50% of rated voltage
  • Automotive - Typically 50% derating per AEC guidelines

DC Bias Effect

Class II ceramics (X7R, X5R) exhibit capacitance reduction under DC voltage. The effect is more severe with smaller case sizes and higher capacitance values. Always consult DC bias curves in the datasheet.