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.

Supply change (V)

Required number input.

Output change (V)

Required number input.

Compute the power supply rejection ratio in decibels as 20 x log10(delta Vsupply / delta Vout); both deltas must be positive. 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]

PSRR (dB)

The resulting psrr 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.

• Op-Amp PSRR dB to Linear

  Convert power-supply rejection ratio from voltage-ratio decibels to a linear rejection factor, 10^(PSRR/20). A 80 dB PSRR means a 10,000:1 small-signal voltage rejection at the stated frequency.

• CMRR dB

  Compute the common-mode rejection ratio in decibels as 20 x log10(differential gain / common mode gain).

• SINAD dB

  Compute SINAD in decibels as 20 x log10(Vfundamental / sqrt(noise^2 + distortion^2)); there must be some noise or distortion.