输入防插错过压保护电路

http://www.cirmall.com/circuit/10893/%E7%9B%B4%E6%B5%81%E8%BF%87%E5%8E%8B%E4%BF%9D%E6%8A%A4%E7%94%B5%E8%B7%AF#/details

http://www.360doc.com/content/18/0110/11/21923670_720732097.shtml

http://www.eefocus.com/analog-power/424178

目前遇到的情况是：单板12V输入，经常会误插48V电源适配器