开关电源反馈环路设计笔记 The NCP1271 is one of the latest fixed-frequencycurrent-mode PWM switching controllers with(1) adjustable Soft-Skip standby operation for low-levelaudible noise, (2) integrated high-voltage startup for savingstandby power, (3) timer based overload fault detection, and(4) internal latch protection features. Table 1 summarizes allthe features of an NCP1271 based power supply.