Sinusoidal Pulse Width Modulation Design Based DDS

FPGA chip using Cyclone series designed and implemented a new type of sinusoidal pulse width modulation (SPWM) generator. The generator used direct digital synthesis (DDS) technology with DSP Builder (FPGA chip supported the corresponding algorithm sub-circuits) discreteness as the hardware middle layer, produced triangle and sine modulated carrier wave which can be controlled in frequency, phase, amplitude. After comparator comparison, the output state was automatic overturn at the time of the waveform intersection, brought SPWM waveform to achieve the control of corresponding switching devices on-off. This method avoided compiling complex hardware program, at the same time ensured the scalability of the system, improved the development efficiency and met the requirements of embedded system, but also has on-site programmability. The simulation results show that the SPWM waveform can neatly achieve the adjustment about frequency, phase, amplitude, and have high frequency resolution.