An isolated DC-DC converter with fully integrated magnetic core transformer

this work presents an isolated DC-DC converter with fully integrated magnetic core transformer. The converter achieves best-in-class efficiency and EMI performance which are most concerned for isolated DC-DC converter with on chip transformer. The proposed chip-level isolated DC-DC converter contains an integrated transformer with 4 mu m thick stacked layers CoZrTa magnetic core, a symmetric pre-driver, a full-bridge driver, modified LLC resonance network, a full-wave bridge rectifier with on-chip Schottky diode and type II compensation network. Fully symmetric architecture and accurate timing control are utilized to minimize the radiated emissions and maximize the efficiency. In comparison with state of the art the measurement results demonstrate proposed DC-DC converter achieves best-in-class efficiency (46%) and EMI performance (pass CISPR22 Class B limit with 10dB margin) by maintaining a high quality factor of 11 for transformer at much lower frequency (25MegHz).