(2)过压保护电路:当N801⒃脚(Vcc)电压超过15.7V时,N801内部过压比较器动作,使N801⒁脚输出脉冲被抑制,开关电源处于过压保护状态。 (3)欠压保护电路:当N801⒃脚电压下降到低于7.4V时,经N801⒃脚内部Vcc控制触发器与逻辑处理器,使N801⒁脚输出PWM脉冲被抑制,开关电源处于欠压保护状态。当以上三种任何一类保护处于保护状态时,都使开关电源停振而无输出电压,因此,若要重新启动开关电源,则N801⒃脚电压须低于5V,才使N801⒃脚内 (2) Overvoltage protection circuit: When N801 pin (Vcc) voltage exceeds 15.7V, N801 internal overvoltage comparator action, so that N801 pin output pulse is suppressed, the switching power supply is in overvoltage protection state. (3) Under-voltage protection circuit: When the voltage of N801 pin drops below 7.4V, the N801 pin’s internal PWM control flip-flop and logic processor will make the N801 pin output PWM pulse be suppressed and the switching power supply is under-voltage protection. When the protection of any of these three types of protection are in the state, the switching power supply is stopped without vibration output voltage, so to restart the switching power supply, the N801 ⒃ pin voltage must be lower than 5V, N801 ⒃ pin