N-type metal-oxide-semiconductor logic uses
n-type field effect transistors (
MOSFETs) to implement
logic gates and other
digital circuits. These nMOS transistors operate by creating an
inversion layer in a
p-type transistor body. This inversion layer, called the n-channel, can conduct
electrons between
n-type "source" and "drain" terminals. The n-channel is created by applying voltage to the third terminal, called the gate. Like other MOSFETs, nMOS transistors have four modes of operation: cut-off (or subthreshold), triode, saturation (sometimes called active), and velocity saturation.