TDK Corp. has introduced two new types of the EPCOS InsuGate series (B78541A) transformers, part of the UI7 platform. These compact SMT transformers with a high working voltage target gate-driver applications for IGBTs and MOSFETs in e-mobility (qualification according to AEC-Q200 and the AQG vibration profile) and industrial electronics.
Thanks to their low coupling capacitance of only 4 pF, the SMT transformers are also suited for use with silicon-carbide or gallium-nitride semiconductors, TDK said.
These transformers feature a MnZn ferrite core and are designed for operating frequencies of 100 kHz to 500 kHz and operating temperatures of -40°C to 150°C. The transformation ratios of the windings are 1:1.08 for the B78541A2467A003 and 1:1.07:0.6 for the B78541A2492A003.
TDK said shorter clearances and creepage distances are possible compared to conventional insulated or potted components, despite the dimensions of only 13.85 × 10.5 × 9.2 mm (L x W x H). This is attributed to the transformers’ highly resistive plastic material with a CTI ≥ 600 and the special coil design.
The InsuGate UI7 platform offers creepage distances between primary and secondary windings of >9.2 mm. Clearance distance is 8.14 mm. The transformers meet IEC 61558 for reinforced insulation for working voltages up to 300 V (AC) or 700 V (DC) for basic insulation with a partial discharge extinction voltage of at least 840 V (peak voltage) and AC high-voltage testing at 3 kV (50 Hz, 1 s).
The new UI7 family includes two reference models to enable winding configurations for forward and push-pull topologies with the appropriate number of outputs. Applications include switched power supplies, gate drivers, isolated DC/DC converters and galvanically-isolated single-channel IGBT drivers.