This paper describes a stability analysis of single-phase sinusoidal current input converter without sinusoidal standard source voltage waveform. First, the pulse width modulation (PWM) operation model of sinusoidal current input converter was constructed. Then, the PWM operation model was analyzed with discrete time quaternization and z conversion. The analysis formulated the PWM period limit. Based on the analysis formulation, it was clarified that the stability limit of PWM frequency and the reactance value of the power supply reactor are inversely proportional. This implies that when the reactance value decreases due to the miniaturization of the power supply reactor, it is necessary to set the PWM frequency higher. The effectiveness of the PWM period limit was confirmed via simulation and actual circuit tests. As test conditions, the reactance value and PWM frequency of the power supply reactor are changed. The test results show the vibration of the power supply current waveform and the results of the current harmonics before and after the stability limit.