A current mirror circuit having formed in a semiconductor: a pair of transistors arranged to produce an output current through an output one of the transistors proportional to a reference current fed to an input one of the pair of transistors; a resistor comprising a pair of spaced electrodes in ohmic contact with the semiconductor, one of such pair of electrodes of the resistor being coupled to the input one of the pair of transistors; and circuitry for producing a voltage across the pair of electrodes of the resistor, such circuitry placing the resistor into saturation producing current through a region in the semiconductor between the pair of spaced ohmic contacts, such produced current being fed to the input one of the transistors as the reference current for the current mirror.