RESEARCH
High Efficiency CLL Resonant Converter with Synchronous Rectifier
Year: 2009
Fig. 1. Circuit of LLC resonant converter.
The air gap of the CLL resonant converter transformer is omitted to eliminate fringing effect. Because of very high magnetizing inductance, the transformer primary side current is in phase with the secondary side current. Thus, SR can be easily driven. Moreover, resonant inductance is integrated with the transformer to reduce the passive component volume.
Fig. 2. Circuit of CLL resonant converter.
Fig. 3. LLC transformer with gap
(severe fringing effect).
(severe fringing effect).
Fig. 4. CLL transformer without gap
(little fringing effect).
(little fringing effect).
Fig. 5. Primary and Secondary current of LLC transformer (out of phase).
Fig. 6. Waveforms of CLL current driven SR.
