An electrical current transducer including a magnetic core and a magnetic field detector module, the magnetic core and magnetic field detector module each forming a single unit separably mountable around a primary conductor and to a circuit board, the magnetic core having a general U shape including an end branch and lateral branches extending the end branch to respective free ends, the magnetic field detector module being positioned between the lateral branches and extending across a whole width of a gap formed between the lateral branches. The magnetic field detector module includes at least one magnetic field sensing cell, a pair of magnetic concentrators arranged in mirror opposition forming a magnetic field gap therebetween in which the at least one sensing cell is positioned, and an insulating body supporting the magnetic concentrators and at least one sensing cell.