PND(个人导航设备)一类的汽车配件通常会用一个插入到点烟器的简单适配器,获得自己的电源并充电。不过,有时候可能想同时为两个设备供电或充电。图1中的电路可以完成这个任务。IC1可从任何7.5V～76V输入电压产生5V输出,这个电压范围有足够宽度,包含了汽车电池电压与有负载突降时的40V尖峰之和。IC使用简单,因为它只有一个内部功率开关,不需要补偿电路。 Auto parts such as PNDs typically use a simple adapter that plugs into the lighter to gain their own power and charge it. However, sometimes you may want to power or charge both devices at the same time. The circuit in Figure 1 can accomplish this task. The IC1 produces a 5V output from any 7.5V to 76V input voltage. This voltage range is wide enough to include the sum of the car’s battery voltage and the 40V spike at load dump. The IC is easy to use because it has only one internal power switch and no compensation circuitry.