Phase-cutdimmable LED driver development has progressed significantly over the past few years with single-stage power converters becoming the mainstream choice for lamp drivers. This paper presents a review of the key problems related to leading-edge and trailing-edgedimmer compatibility. Several input current control methods are discussed and compared based upon their impacts on dimming performance. It also discusses the pros and cons of three power conversion topologies in dimming applications. An integrated circuit controller, which exemplifies the latest control technology, is introduced at the end.