Designing more circular products is essential to reaching Sustainable Development Goal 12, Responsible Consumption and Production, which is anticipated to be achieved by 2030. To achieve progress toward a circular economy in power electronics, discarded products, modules, or components must be recovered. This requires the implementation of End-of-Life (EoL) strategies. In order to maximize the high-value circularity efficiency of a power electronic product, EoL choices and constraints should be taken into account early on in the design phase. Since disassembly is a known bottleneck in EoL practices, design to enable disassembly is essential. Modularity enhances the product's reconfigurability and disassemblability, its reuse in other product families, as well as the product's maintenance, and serviceability. So, it is anticipated that this multiple life cycle thinking enabled by modularity would contribute to the transition towards more circular power electronic designs. Therefore, in this paper, we aim to consider modular designs of power electronic converters (PECs) and categorize them. As a result of a corresponding discussion about the existing PECs, we point out the general potentials to enhance circularity by modularity applied to PECs.