He formerly served as the Croatian Minister of Science and Technology in the fourth and the fifth Government of the Republic of Croatia from February 1993 to November 1995.
[3] He worked as a postgraduate assistant at the Electronics Department of the Rudjer Bošković Institute from 1973 to 1975, and at the Institute of Electrical Engineering in Zagreb from 1975 to 1976, on the problems of an implementation of computers in nuclear power plants, thermal power plants and dispatch centers.
Since 1976, he has been employed as an assistant at the Faculty of Electrical Engineering, at the Department of Electronic Systems and Information Processing.
[2] In 1978, he received the federal award Dr. Vratislav Bednjanić for the master's thesis entitled "Processor for digital filtering", in 1986 he won the Josip Lončar silver plaque for his doctoral dissertation and in 1995 he was awarded the Order of Danica with the image of Rudjer Bosković.
[2] In 1997 prof. Jeren received National Science Award and in 2004 Golden Plaque "Josip Lončar" for dedicated teaching and scientific work and exceptional contribution to the development of the Faculty of Electrical Engineering and Computing.