Decoupling Capacitor Calculator
Calculate optimal bypass capacitor values for your ICs
Input Parameters
Results
Recommended Capacitor
Minimum: 2.00 µF
Actual Ripple
45.45 mV
Ripple %
1.38%
Best Practices
- Place capacitors as close to IC pins as possible
- Use multiple capacitor values for broadband filtering
- Keep traces short and wide
- Connect directly to ground plane via
Typical Combinations
Digital ICs
100nF + 10µF per power pin
High-Speed Circuits
10nF + 100nF + 10µF
Analog ICs
100nF + 10µF ceramic
Understanding Decoupling Capacitors
Why Decoupling Matters
Decoupling capacitors provide local energy storage to supply transient current demands from ICs. Without proper decoupling, voltage rails can droop during switching events, causing logic errors or analog noise. They also filter high-frequency noise from the power supply.
Capacitor Selection
Choose ceramic capacitors (X5R, X7R) for high-frequency decoupling due to their low ESR. Combine with larger bulk capacitors (electrolytic or tantalum) for low-frequency filtering. The resonant frequency of the capacitor should match the noise frequency you want to filter.