A Novel Cross-Over CMR Transformer Technology for Magnetic Isolation Gate Driver Applications

A novel Cross-Over CMR transformer technology is proposed. The CMR (common-mode rejection) problem of magnetic isolation signal transmission is solved by the secondary Cross-Over differential coils and ANPTM (alternating narrow pulse transmission mode). Based on CSMC 1um BCD technology platform, the simulation results show that compared with the traditional magnetic isolation, the CODT (Cross-Over differential transformer) technique has a lower mismatch and smaller area. The circuit transmission delay reduces by 30% to 23ns with signal transmission frequency as high as 10MHz. The isolation voltage reaches 5kV while improving CMR (CMR greater than 50 kV/μ s). The proposed technology can be applied in high voltage floating gate driver for IGBT, CoolMOS, and even GaN HMET devices.