Electronic device including at least: - a reference resistor (105, 140, 142); - two first terminals (102, 104) between which the reference resistor (105, 140, 142) is connected, and two second terminals (106, 108) between which a modified impedance value of the reference resistor (105, 140, 142) is obtained; - a first circuit (110, 112) configured to apply between the two second terminals (106, 108) a voltage substantially equal to that between the two first terminals (102, 104); - a second circuit (114, 120, 126, 134) configured to flow between the two second terminals (106, 108) a second current the value i1 of which corresponds to a fraction of the value i0 of a first current intended to flow in the reference resistor (105, 140, 142) between the two first terminals (102, 104) such that their values verify the relationship (i1/i0) < 1; wherein the second circuit (114, 120, 126, 134) includes at least: - one first FET transistor the source and drain of which are each connected to one of the two second terminals (106, 108) and the gate of which is configured to receive an electric potential from the second circuit (114, 120, 126, 134) and the value of which depends on that of the first current; - a first current mirror comprising at least the first FET transistor and a second FET transistor; - a second current mirror comprising at least third and fourth FET transistors (122, 124) of a different type from that of the first and second FET transistors (116, 118); wherein the first and second FET transistors (116, 118) have channels with dimensions different from each other and/or the third and fourth FET transistors (122, 124) have channels with dimensions different from each other; wherein the first circuit (110, 112) includes one first operational amplifier connected as a comparator or a follower, coupled between one of the two first terminals, one of the two second terminals, and the second circuit (114, 120), and configured to recopy the electric potential of said one of the two first terminals on said one of the two second terminals; and wherein the first circuit further includes a second operational amplifier connected as a comparator or a follower, coupled between the other of the two second terminals and the other of the two first terminals and configured to recopy the electric potential of said other of the two first terminals on said other of the two second terminals, or, when the first operational amplifier is connected as a comparator, the other of the two first terminals is directly connected to the other of the two second terminals. - a reference resistor (105, 140, 142); - two first terminals (102, 104) between which the reference resistor (105, 140, 142) is connected, and two second terminals (106, 108) between which a modified impedance value of the reference resistor (105, 140, 142) is obtained; - a first circuit (110, 112) configured to apply between the two second terminals (106, 108) a voltage substantially equal to that between the two first terminals (102, 104); - a second circuit (114, 120, 126, 134) configured to flow between the two second terminals (106, 108) a second current the value i1 of which corresponds to a fraction of the value i0 of a first current intended to flow in the reference resistor (105, 140, 142) between the two first terminals (102, 104) such that their values verify the relationship (i1/i0) < 1; - one first FET transistor the source and drain of which are each connected to one of the two second terminals (106, 108) and the gate of which is configured to receive an electric potential from the second circuit (114, 120, 126, 134) and the value of which depends on that of the first current; - a first current mirror comprising at least the first FET transistor and a second FET transistor; - a second current mirror comprising at least third and fourth FET transistors (122, 124) of a different type from that of the first and second FET transistors (116, 118); wherein the first and second FET transistors (116, 118) have channels with dimensions different from each other and/or the third and fourth FET transistors (122, 124) have channels with dimensions different from each other; wherein the first circuit (110, 112) includes one first operational amplifier connected as a comparator or a follower, coupled between one of the two first terminals, one of the two second terminals, and the second circuit (114, 120), and configured to recopy the electric potential of said one of the two first terminals on said one of the two second terminals; and wherein the first circuit further includes a second operational amplifier connected as a comparator or a follower, coupled between the other of the two second terminals and the other of the two first terminals and configured to recopy the electric potential of said other of the two first terminals on said other of the two second terminals, or, when the first operational amplifier is connected as a comparator, the other of the two first terminals is directly connected to the other of the two second terminals.