PI专利网站:
1、http://www.powerint.com/company/patents/trademarks
2、http://patft.uspto.gov/netacgi/nph-Parser?Sect1=PTO2&Sect2=HITOFF&p=1&u=/netahtml/search-bool.html&r=0&f=S&l=50&TERM1=power+integrations&FIELD1=ASNM&co1=OR&TERM2=power+intergrations&FIELD2=ASNM&d=ptxt
附上两个搜索和下载专利的网站:
http://patft.uspto.gov/netahtml/PTO/index.html
http://www.freepatentsonline.com/