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.

Fundamental RMS amplitude

Required number input.

Largest spur RMS amplitude

Required number input.

Compute SFDR in dBc as 20log₁₀(fundamental RMS amplitude/largest spur RMS amplitude), excluding DC. Use amplitudes measured in the same unit from one spectrum. 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]

SFDR dBc

The resulting sfdr dbc returned as a number.

• Compact electronics formulas omit some combination of tolerances, temperature drift, bandwidth, loading, parasitics, noise spectrum, nonlinearity, clipping, calibration, layout, and device-specific limits. Typical datasheet values are not guaranteed limits.
• 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.

• ADC Total Harmonic Distortion

  Calculate THD from RMS harmonic amplitudes relative to the fundamental: sqrt(sum of harmonic squares)/fundamental. Output is percent and dBc; include only the harmonics specified by the measurement method, excluding noise and DC.

• SFDR dB

  Compute the spurious-free dynamic range in decibels as the carrier level minus the largest spur level, both in dBm.

• Powder Core AL Inductance

  Calculate inductance L=AL·N² from a core's inductance factor and turn count. AL and output use the same unit per turn squared; account for DC bias separately because effective permeability can fall.