Design and control of a demagnetization circuit for permanent ON OFF operation in pulse transformer gate driver

The paper deals with the design and the implementation of a new gate driver structure used to polarize and to control MOS gated power switches such as MOSFETs and IGBTs. Including electrical isolation, this driver enables to transfer the required charges directly to the gate to source/emitter electrodes of the power device through an HF transformer. Based on a pulse transformer gate driver circuit for high frequency applications, we modified the initial structure by introducing a demagnetization circuit for the transformer; therefore, it is now able to operate at low even very low switching frequency and any duty cycle without increasing pulse transformer size, removing a classical limitation of pulse transformer based gate drivers. Several gate driver primary side units can be integrated to minimize system size and increase robustness. On the secondary side, elementary drive circuit components can also be integrated simplifying the implementation. The operation principle and the implementation of the gate driver will be addressed.