SMT current sense transformers have a turn ratio of 1:100
Designed for automotive electronics, two SMT current sense transformers have been introduced by TDK. Based on an EP7 ferrite core, the B78417A2185A003 is designed to measure pulse currents of up to 20A. DC resistance is 1.3mΩ on the primary side and 3.7Ω on the secondary side.
The B78419A2251A003, which is based on an EP10 ferrite core, is designed to measure currents of up to 30A. DC resistance is 0.5mΩ on the primary side and 2.7Ω on the secondary side.
Operating from a -40 to +150°C temperature range, the transformers have a turn ratio of 1:100. Between primary and secondary sides, the test voltage is 2800VDC. The devices, which are qualified to AEC-Q200, feature creepage and clearance distances that meet the requirements for basic insulation according to IEC 60664.
The SMT current sense transformers are designed for use in 48V automotive power systems. The devices are also suitable for xEV applications, where the components can be used to measure the currents of the electric drives.
The B78417A2185A003 measures 0.6x12.2 x11mm, while the B78419A2251A003 measures 12.8x13.6x14.4mm.