This paper represents one of the development stages of the converter (LED driver) operating in amplitude mode light regulation. The principles of construction of the MOSFET driver circuits for the schematic with two n-channel MOSFET transistors are described. Also the schematic where high side transistor is substituted with p-channel transistor is considered. Utilization of the p-channel transistor allows eliminating necessity of using of isolated power supply for the driver of the high side transistor. In the last two sections of the article the losses in driver circuits are considered. This allows evaluating the scope of application for all considered approaches. From point of view of transistor driver losses it is preferable to use schematic with p-channel transistor at lower input voltages (in range of 12…30V) and higher switching frequencies.