Abstract: A system for determining the instantaneous amplitude (a) and phase (&phgr;) of an analog sinusoid includes a sensor which produces the analog sinusoid output in response to the measurement of a parameter, an analog-to-digital converter which receives the analog sinusoid from the sensor and converts the analog sinusoid to a digital sinusoid, a delay device which receives the digital sinusoid and produces an in-phase signal (I) associated with the digital sinusoid, a transformer which receives the digital sinusoid and produces a quadrature signal (Q) associated with the digital sinusoid by introducing a phase shift plus a delay to the digital sinusoid, an amplitude computation device which receives the in-phase (I) and quadrature (Q) signals and computes the instantaneous amplitude (a) of the digital sinusoid by processing the in-phase (I) and quadrature (Q) signals according to the equation a={square root}{square root over ((Q2+I2))} and a phase computation device which receives the in-phase (I) an