Fast Driving Circuit With Active Discharged Circuit for Power PMOS and Its Parameter Design Method

Power MOS has been widely used in power converters.

This is due to its characteristics of easy driving [1], fast switching speed [2], low on-state resistance [3], etc. According to the type of channel carriers, MOSFETs can be divided into NMOS and PMOS. Although NMOS has advantages over PMOS in switching performance and on-state resistance, it is not suitable for Buck [4], Buck-Boost [5] converters and LDO [6], because its gate requires a higher drive voltage relative to the input. Therefore, the isolated drive or bootstrap circuit must be used in this case. PMOS is very suitable for applications in these situations, and it can avoid the above problems of NMOS. Additionally, PMOS has the advantages of lower reverse leakage current and better noise performance. PMOS is commonly used in the high-side driving of the bridge circuits, because of its simpler peripheral circuit and higher application reliability [7]. Besides, PMOS is also used in LDO because it has a lower dropout voltage [8].