Use this electronics calculation for a first-pass component, converter, signal, motor, or sensor estimate when the stated operating conditions and units match the device data.

Transient current (A)

Required number input.

Allowed droop time (ns)

Required number input.

Allowed droop voltage (V)

Required number input.

Compute the decoupling capacitance C = I x dt / dV needed to supply a transient current for a droop time within an allowed droop voltage. The tool evaluates the supplied inputs together and returns the named outputs below; it does not infer omitted operating conditions or change the units shown.^[1]

Decoupling capacitance (uF)

The resulting decoupling capacitance returned as a number.

• Capacitance, ESR, leakage, ripple rating, lifetime, and self-resonance vary with frequency, temperature, DC bias, aging, dielectric, package, and mounting. Nominal capacitance alone does not determine in-circuit impedance or reliability.
• Use finite inputs in the displayed units and preserve more precision than the final presentation requires. Independently verify safety-critical, financial, compliance, or production decisions.

Check the result against the current datasheet and worst-case operating corners, then verify the circuit or measurement with simulation and bench testing where failure matters.

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• PSU Holdup Cap

  Compute the bulk capacitance needed to hold up a power supply output for a ride-through interval.