1Sinewave Generation Using Bit-Streams

Abstract—A new method for the generation of high quality sinusoidal signals is presented. Multi-bit binary signals are represented using uniformly weighted single bit-streams which can then be processed by digital logic. Building blocks useful for the construction of the sinusoidal generator are also presented. The bit-stream representation has the advantage of having the characteristics of a classical PWM signal and hence can be used to drive high power switching devices with minimal conditioning. The technique is simple and can be easily implemented using digital logic on an field programmable gate array (FPGA). The operation of a single phase inverter using the proposed technique is demonstrated using an Altera StratixTM FPGA and a custom built power stage. The complete digital design uses less than 200 logic elements (LE). The performance of this technique is quantified using simulations and practical measurements. Prac-tical implementations lead to total harmonic distortion (THD) measures ranging between 0.75 % to 4.92%. Index Terms—PWM generation, bit-streams, inverter, variable frequency drive