SIM card holder provides the interface of communication between cell phone and SIM card in cell phone, and it contacts with SIM card through the spring piece on the holder, so if the spring piece is deformed, it will lead to SIM card failure, such as “check card”, “insert card”, etc. SIM card power supply is 3V and 5V, early mobile phone SIM card is usually 5V, now it is more often 3V. The SIM card clock is 3.25MHz; I/0 terminal is the data input and output port of SIM card. When SIM card circuit is activated, pulse signal shape can be measured in SIM card clock and card data port.
The basic knowledge of IM card holder, SIM card holder is the SIM card in the cell phone, according to different cell phone model specifications to distinguish, SIM card holder can be divided into large, medium and small card, and SIM card holder have several basic SIM card interface terminal: namely, card clock (SIMCLK), card reset (SIMRST), card power (SIMVCC), ground (SIMGND) and card data (SIMI/0 or, SIMDAT). (SIMI/0 or, SIMDAT).
SIM card holder pin use characteristics, 1, SIM card holder storage capacity: general SIM card holder has 8KB storage capacity, in addition there are capacity of 16K/32K/64K/128K SIM card holder respectively. 2, SIM card holder use temperature: standard temperature -25 + 70 ℃, the limit of each use shall not exceed 4 hours, the total use shall not exceed 100 times. 3, the service life of SIM card holder: physical life is dependent on the number of customer plugging and unplugging, about 10,000 times; while the life of integrated circuit chip depends on the number of data memory writes, and the indicators of different manufacturers are different.
