This paper is focused on the analysis of an economic single-phase to three-phase converter that has a reduced number of power switches and avoids the use of an input filtering inductance. This structure consists fundamentally on a four-leg converter, including the inverter and the rectifier. The topology is especially interesting for low-cost low-power motor drive applications. Continuous and discontinuous carrier-based PWM are applied and compared in this four-leg system to define which of them achieves better performance of the converter. Switching losses on the devices are also evaluated for the proposed modulation techniques. The work concludes showing some experimental results