TDK Corp. has introduced two EPCOS SMT current sense transformers for automotive electronics. The B78417A2185A003 incorporates an EP7 ferrite core and measures 10.6 x 12.2 x 11 mm. It measures pulse currents up to 20 A. The dc resistance is 1.3 mΩ on the primary side and 3.7 mΩ on the secondary side. The B78419A2251A003 contains an EP10 ferrite core and measures 12.8 x 13.6 x 14.4 mm. It measures pulse currents to 30 A. Its dc resistance is 0.5 mΩ on the primary side and 2.7 mΩ on the secondary side.
Both transformers have a turn ratio of 1:100 and are suited for operating temperatures of -40 to +150 °C. The test voltage between primary and secondary is 2800 Vdc. The creepage and clearance distances meet the requirements for basic insulation per IEC 60664.
The transformers are designed for use in 48-V automotive power systems as well as all xEV applications, where the components can be used to measure the currents of the electric drives.