Explanation of the differences between ON/OFF operation of BJT and MOSFET.
(1) Base current of BJT starts flowing when base voltage increases, and collector current is in proportion to this base current. This flow starts at about 0.7 V. This voltage is called the base-emitter threshold voltage (VBE). In order to make collector current flow, it is necessary to supply the base current and continuous driving power is required. (Low drive voltage, continuous driving power required)
(2) Since the MOSFET forms a channel according to the gate-source voltage, this voltage must be a certain voltage or more. Once the channel is formed, the ON state continues and the drain current continues to flow, and so the power required for the driving is small. By discharging the charge accumulated in the gate and removing the channel, it shifts to the OFF state. (Driving voltage higher than BJT, small driving power)