The paper presents four methods for hardware and software generation in real time of sine waves suitable for PWM circuits. The sine waves are derived from a truncated modified cosine Taylor series, wt(f-wt) function, a digitally filtered trapezoid, and a second-order differential equation. Triplen injection is incorporated by the addition of a defined magnitude triangular waveform of three times the fundamental frequency. Each sine-wave generating technique is implemented, as applicable, in a programmable logic cell array and/or in microprocessor-based software. In each case, the output spectra and total harmonic distortion are compared with computer-simulated results.