MOSFET drain/source charge partition under nonquasi-static switching

The channel charge partition of metal-oxide-semiconductor transistors in nonquasi-static switching has been studied. A new approach, with the help of a two-dimensional device simulator is used to separate the direct current and transient current component during device switching. Unlike the commonly accepted 40/60 drain/source channel charge partition ratio, our results show that it is closer to the 0/100 as long as the switch speed is higher than the channel charging time. The result is important for pass-gate type circuits to evaluate the amount of charge transferred to the source and drain nodes.