Common mode voltage (CMV), produced by conventional high-frequency pulsewidth modulated (PWM) voltage source inverters (VSIs), is a major area of interest in applications such as transformerless Photovoltaic (PV) systems, electric motor drives, as well as grid-connected inverters. Since the VSI can only be utilized as a buck inverter, the AC output voltage should be boosted up using an extra boosting stage either in the DC side or in the AC side. So, to reduce the cost, complexity, size, and weight of the converter, the additional boosting stage must be eliminated by using single-stage DC-AC converters, which have the buck-boost feature in a single stage. This paper investigates the induced CMV issue due to a recent single-stage DC-AC inverter topology, split-source inverter (SSI), which has not been comprehensively examined. The CMV waveforms for both VSI and SSI have been analyzed and compared. Furthermore, the paper proposes a discontinuous PWM (DPWM) to alleviate the CMV effect. To check the validity of the proposed analysis, simulations were done using MATLAB/Simulink model. It was shown that a significant CMV reduction could be achieved using the proposed modulation technique.