An electronic trimming circuit carries out a trimming operation on portions of an integrated device. The circuit includes N trimmable interconnected resistances, each connected in parallel to a respective shunt fuse. N trimming transistors are each connected to a respective one of the shunt fuses to force therethrough substantially the whole current flowing in the respective trimming transistor. N bias networks are each functionally connected to a control terminal of a respective one of the trimming transistors to directly bias an active junction thereof. An externally driven heating device is thermally coupled with the active junctions of the trimming transistors adapted to raise the temperature thereof.