ZHCSIL2C July 2018 – March 2022 UCC24624
PRODUCTION DATA
Right after the SR MOSFET turn on, the SR is driven fully on. For the LLC resonant converter, the SR current rises from zero. It is desired to keep the SR on during this situation and allow the current to rise to a high enough level to maintain the full conduction time. In UCC24624, after the SR is turned on, a minimum on time blanking of 475 ns is implemented. During the on-time blanking time, the SR keeps conducting regardless of its drain to source voltage. This on-time blanking limits the maximum switching frequency of the LLC converter to 625 kHz.