This invention provides a circuit and a method for interfacing a subscriber information module, SIM to a base band controller for a mobile phone. It provides voltage level shifting to allow a low voltage base band controller chip to interface to a higher voltage SIM card. The higher voltage bus goes...http://www.google.com.tw/patents/US6952596?utm_source=gb-gplus-share專利 US6952596 - Active subscriber information module
