Local biasing and the use of nullator-norator pairs in analog circuits designs

Although local biasing of components used in an analog circuit is shown to be a very attractive design methodology, significantly simplifying the design procedure (Hashemian, 2005), it makes the DC supplies distributed and often not in desire locations in the circuit. In response to this problem a new technique is developed that in conjunction with the local biasing it handles the DC supply sources very smoothly and transfers them to the designated locations in the circuit, specified for global biasing. The technique utilizes nullator-norator pairs to do the required source transformation. Overall, the technique totally avoids nonlinearity in the operation due to a novel nullator modeling that is presented for locally biased components. For the lack of space, the method is only applied to MOS transistors here, but it can simply be extended to BJTs as well. As an example, a two stage amplifier with feedback is used to demonstrate the methodology.