Sensitivity of dynamic MOS flip-flop sense amplifiers

An approximate analytic expression for the sensitivity of a dynamic flip-flop sense amplifier is derived. The calculation includes the imbalance of the flip-flop, and the approximate solution is given by means of Lynch and Boll´s method. The sensitivity, which is defined by the minimum difference in input voltages, consists of two terms; one is the center voltage deviation, which is characterized by the imbalance of the device parameters, and the other is the insensitivity-width term, which greatly depends on the choice of circuit parameters. In normal highly sensitive sense amplifiers used in dynamic memories, the insensitivity-width term can be sufficiently small and the sensitivity is dominated by the imbalance of device parameters such as threshold voltages, conductances, and capacitances.