This paper is focused on the design and the realization of two high-current probes (up to 100 A) whose bandwidths range from dc to 50 MHz. The performance has been met by the association of an active Hall sensor and a passive current transformer. This association will be named an "active current transformer." It will be shown that it has better frequency performance than the classical closed-loop current transducer, usually used for high-current measurements but frequency limited. The electromagnetic interference (EMI) issues, due to the sensor electrical environment are respected thanks to the shielded structure and special inner arrangements of the Hall sensors. Because of its large bandwidth, its large current range, and its EMI ruggedness, this current probe is well matched to power electronics measurements. Index Terms-Current probe, current transformer, electromagnetic interference (EMI), Hall sensor, power electronics.