常用的sch元件库，里面包含有最常用的库。以方便大家对sch的使用,Sch common library, which contains the most commonly used database. In order to facilitate the use of sch

MAX539是MAXIM公司生产的快速D/A转换器,它具有接口简单、转换时间短、功耗低、体积小等优点。可用于便携式设备和工业控制等方面。文中介绍了D/A转换器MAX539的性能特性、工作原理及在单片机系统中的应用。给出了MAX539与单片机的接口程序。 -MAXIM MAX539 is produced by fast D/A converter, it has a simple interface, conversion time is short, low power consumpti