The cell density, a favored term within the power MOSFET industry, conveys that the power MOSFET structure consists of many cells connected in parallel. In principle, these cells constitute a resistive path for drain-source current. Electrically, these cells are parallel connected resistors, rDS(on) s. Each cell - being identical in structure and electrical characteristics shares the current equally when the device is on. This property enables design of a MOSFET with a current-sensing feature.