A method to reduce process-related sensitivity in sub-threshold ICs and its circuit implementation

This paper provides a novel bulk-compensated technique used in sub-threshold integrated circuits (ICs), solving the problem that MOS transistors in the sub-threshold area are extremely sensitive to the issue of process variation. The bulk-compensated technique builds up a unique "detecting-feedback" loop, and achieves an effective compensation for the process-related fluctuation of MOS transistors through bulk potential modulation. A simple circuit implementation of the proposed technique is also presented, which is implemented in 0.13 μm CMOS mixed-signal process. With the introduction of the bulk-compensated circuit, the sensitivity of MOS transistors to process variation in the sub-threshold area is greatly reduced.