This entry addresses the topologies of the single-stage isolated matrix inverters with a grid-side switching stage based on the current source inverter (CSI). These inverters have been proposed for the uninterruptible power supplies, high and low-voltage/power photovoltaic systems, low-power fuel cell, different low- and high-voltage battery and/or electric vehicle chargers, audio amplifiers. The fully controlled switches on both terminals of these converters typically can provide the bidirectional power transfer capability, which is also addressed for most of the topologies. The other advantages include soft-switching of semiconductors and absence of the bulky DC-link capacitor. Average efficiency of today’s isolated matrix inverters is comparable with the two-stage power converters; however, due to absence of DC-link they can provide higher reliability and lower cost.