Epcos has developed two series of current sense transformers that are particularly suitable for compact DC/DC converters. They have dimensions of 8.33 x 7.11 mm² and 4.7 x 3.5 mm². The primary winding is already integrated in all types. Both series cover winding ratios from 1:20 to 1:125. The first series represents a compatible solution for existing designs based on an EE5 core.

The DC resistance of the primary winding is 0.8 mΩ and the rated current is 20 A for all types of this series. They have a test voltage of 500 V AC. The second series was developed as a miniature variant with the more compact E4.2 core. The primary winding is integrated in the coil former in a space saving way. Its DC resistance is 2.5 mΩ and its rated current is 7 A. The test voltage of these types is 360 V AC.