The block diagram of a typical switched-mode power supply is shown on this slide. Designed around an LLC resonant converter, it is possible to see three different controller ICs. First, there is a PFC controller for the input stage which provides a semi-regulated, high voltage input to the LLC converter stage. Following that is the resonant controller. ST's original resonant controller was the 6599A, the part being discussed in this tutorial is the 6699, which is a second-generation, improved controller. In the output stage of a half-bridge topology, there will either be diodes or, as shown in the diagram, synchronous rectifiers which require a synchronous rectifier control IC. The SRK2000 is featured in this circuit. Combined with the high-power-density and low dissipation of the LLC half-bridge converter, using synchronous rectification can realize an even smaller form factor and higher efficiency than using conventional diode rectification.