Current mirrors with limiting of linear dynamic range

The paper describes current mirrors with limiting of their linear dynamic range. The first circuit uses the difference between the absolute values of threshold voltages that exists in many CMOS technologies. The second circuit uses the threshold voltage variation caused by the body-effect. The third circuit (for limiting the maximal value of the current mirror output current) and the fourth one (for limiting the minimal value) use an operational amplifier that turns on a driving transistor connected between common connection of the current mirror gates and one of the power supply lines. A special transistor circuit sets two reference voltages with a small difference between them as is required when the third and fourth circuits are used together. The circuits were designed for 0.18 μm CMOS technology and verified by simulation.