Compact SMT current sense transformers for power electronics

The maximum DC resistance on the primary winding is 1.9mΩ. The SMT current sense transformers in the B78419A series are designed with EP10 ferrite cores. These components have dimensions of 12.8x13.6x14.4mm and their measurement range extends up to 30 A. The DC resistance is just 0.5mΩ.

Each series is available with a variety of turn ratios: While the EP7-based transformers are available in four versions with turn ratios of between 1:50 and 1:125, the EP10 transformers offer five versions with turn ratios of between 1:50 and 1:180. The permissible operating temperature range extends from -40 to +150 °C. The transformers are suitable for measuring currents in the frequency range from 50 to 250kHz.

Possible applications include switch-mode power supplies and all types of converters. The test voltage between the primary and secondary sides is 2400VAC and the creepage distances meet the requirements for basic insulation according to IEC 60664. As the components are qualified to AEC-Q200, they can also be used in xEV applications, e.g. for measuring the currents in DC/DC inverters.