Of the five functions and features discussed on the previous slide, the three most critical are the dynamically self-adjusting dead time, the anti-capacitive protection mode, and the enhanced soft-start for extra smooth start-up. The anti-capacitive mode avoids dangerous hard switching, which unnecessarily over-stresses the MOSFETs. This allows the designer to use the best fit MOSFET for the application without having to over-size it, plus it protects the MOSFETs from unsafe or inadequate circuit designs. And because this lowers the stress on the MOSFETs, the designer can realize higher system reliability, or use smaller MOSFETs to achieve the same performance. The self-adjusting dead-time keeps the efficiency high over the full load range, especially at light loads, automatically, and this is a benefit that comes without any hard work being done to achieve it. The dead-time is automatically longer with a light load and shorter at full load. This also enables a more optimized transformer design by enabling the designer to use a higher magnetizing inductance, which keeps magnetizing current lower and efficiency higher. Lastly, the enhanced soft-start for extra-smooth monotonic start-up uses a proprietary circuit which prevents capacitive mode operation and the hard switching that can occur during initial switching cycles, due to the volt-seconds imbalance that can result from charging up a discharged resonant capacitor. Again, these are all important features that will make the L6699 a good choice for an LLC resonant converter. Anyone that is planning to design an LLC converter will want to investigate the L6699 and experience all of these benefits.

