Transformer for Gate Drive Applications

Compact SMT transformers for gate driver applications

TDK presents two new types of the EPCOS InsuGate series (B78541A). These compact SMT transformers with high working voltage are suitable for gate driver applications for IGBTs and MOSFETs in e-mobility (qualification according to AEC-Q200 as well as according to AQG vibration profile) and in industrial electronics. The components with a MnZn ferrite core are designed for operating frequencies of 100 kHz to 500 kHz and operating temperatures of -40 °C to +150 °C. Depending on the type, the transformation ratios of the windings are 1:1.08 (B78541A2467A003) or 1:1.07:0.6 (B78541A2492A003). With a low coupling capacitance of only 4 pF, the SMT transformers are also suitable for use with SiC or GaN semiconductors.

Combining the highly resistive plastic material with a CTI ≥ 600 and the special coil design, shorter clearances and creepage distances are possible compared to conventional insulated or potted components, despite the dimensions of only 13.85 x 10.5 x 9.2 mm (L x W x H). The UI7 platform, for example, offers creepage distances between primary and secondary windings of >9.2 mm. 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 2 g lightweight components meet IEC 61558 for reinforced insulation for working voltages up to 300 V (AC) or 700 V (DC) for basic insulation. This is sufficient for many industrial and automotive applications.

The new UI7 family includes two reference models to allow possible winding configurations for forward and push-pull topologies with the appropriate number of outputs.

Main features and benefits