Statistical modeling and post manufacturing configuration for scaled analog CMOS

Process variations in advanced CMOS process nodes limit the benefits of scaling for analog designs. In the presence of increasing random intra-die variations, mismatch becomes a significant design challenge in circuits such as comparators. In this paper we describe and demonstrate the details of a statistical element selection (SES) methodology that relies on choosing a subset of selectable circuit elements (e.g., input transistors in a comparator) to achieve the desired specification (e.g., offset). Silicon results from a 65nm test chip demonstrate that SES can achieve an order of magnitude better matching than both redundancy and Pelgrom-model sizing given the same core circuit area.