TDK Electronics · TDK Europe


October 30, 2014

SMT current sense transformers for automotive electronics


TDK Corporation presents two new EPCOS SMT current sense transformers for automotive electronics. The first type (B78417A2185A003) is based on an EP7 ferrite core and has dimensions of only 10.6 mm x 12.2 mm x 11 mm. It is designed to measure pulse currents of up to 20 A. The DC resistance is 1.3 mΩ on the primary side and 3.7 Ω on the secondary side. The second SMT current sense transformer (B78419A2251A003) contains an EP10 ferrite core and measures 12.8 mm x 13.6 mm x 14.4 mm. The measurement range of the larger type extends to 30 A. Its DC resistance is 0.5 mΩ on the primary side and 2.7 Ω on the secondary side.

Both transformers have a turn ratio of 1:100 and are suitable for the wide temperature range from -40 to +150 °C. The test voltage between the primary and secondary sides is 2800 V DC. The creepage and clearance distances meet the requirements for basic insulation according to IEC 60664. The new transformers are qualified to AEC-Q200.

The SMT current sense transformers are designed for use in emerging 48-V automotive power systems as well as for all xEV applications, where the components can be used to measure the currents of the electric drives.

Main applications

  • Current measurement in 48-V automotive power systems and in all xEV applications
  • Recording the currents of electric drives

Main features and benefits

  • Rated currents up to 20 A and 30 A, respectively
  • Creepage and clearance distances according to IEC 60664 (basic insulation requirements)
  • Extensive temperature range from -40 °C to +150 °C
  • Qualified to AEC-Q200

Key data

TypeDimensions [mm]Max. current [A]Turn ratioTemperature range [°C]
B78417A2185A00310.6 x 12.2 x 11201:100-40 to 150
B78419A2251A00312.8 x 13.6 x 14.4301:100-40 to 150

Get in Contact

Sales Network & Sites

If you are interested in our products, you will find here an overview of our worldwide sales offices, which you can contact quickly and easily


Product Inquiry

Are you interested in our solutions? Please do not hesitate to contact us! We will be glad to help you.


Tradeshows & Events

Experience TDK live!


Social Media