A high-swing MOS cascode bias circuit for operation at any current level

In this paper, we propose a very simple bias circuit that allows for maximum output voltage swing of MOSFET cascode stages. The proposal is valid for any current density and is technology-independent. Starting from the saturation voltage and from the current density of the cascode stage, we determine the aspect ratio of the transistors in the bias circuit in order to maximize the output voltage swing. Experimental results validate the strategy for designing the bias network.