A system is described for generating a discrete noise-shaped variable switching frequency signal that may be used to define a digital pulse width modulation (“PWM”) period. The system may define a switching frequency waveform that may be used to generate a current switching frequency signal as a function of a system clock. The system may quantize the current switching frequency signal to generate a discrete switching frequency signal that is realizable with the system clock. The system may detect quantization noise and input the noise into the current switching frequency signal to eliminate or reduce discrete tones at the switching frequencies of a PWM signal spectrum.