为NPN型功率管的降压型开关电源芯片设计了一种驱动电路。针对功率管工作在导通状态下的导通损耗和在开关状态转换中的开关损耗,设计了自举电路,使功率管饱和;设计了加速电路,缩短了功率管状态转换所用时间,降低了功率管损耗。在2μm双极型工艺下进行仿真,结果显示,功率管工作在饱和区,导通损耗小,开关转换速度快,可满足高开关频率的要求。 A kind of driving circuit is designed for the buck type switching power supply chip of NPN type power tube. Aiming at the on-state conduction loss and the switching loss in the switching state of the power transistor, a bootstrap circuit is designed to saturate the power transistor. The design of the accelerating circuit shortens the time required for the state transition of the power transistor, Power tube loss. Simulation results show that the power transistor works in the saturation region, the conduction loss is small, and the switching speed is fast, which can meet the requirements of high switching frequency.