Patent attributes
A pulse width modulator for producing a PWM signal having reduced nonlinear distortion through interpolation processing with fewer computation steps is provided. The computational processing, W={1+α(X2−X1)}{0.25 (X1+X2)}+0.5, is performed in accordance with successive sample values (X1, X2) in a PCM data train to determine a weighting factor (W). The computational processing, Xq=0.5·X0(W2−W)+X1(1−W2)+0.5·X2(W2+W), is performed using the sample values (X1, X2), a sample value (X0) previous to the sample value (X1), and the weighting factor (W) to thereby determine an interpolated sample value (Xq) having an amplitude close to that of an original analog signal (X(t)) generating the PCM data train. A point in time (tq) at which a reference signal (R(t)) takes on the interpolated sample value (Xq) is then determined to produce a PWM signal (Spwm) which is logically inverted at the point in time (tq).
