Specifications

TC35 / TC37 Hardware Interface Description
TC35_37_HD_02_V03.10 - Released Page 45 of 92 21.12.2001
3.7.2 Design considerations for SIM card holder
The schematic below is a sample configuration that illustrates the Molex SIM card holder
located on the DSB35 Support Box (evaluation kit used for type approval of the Siemens
TC35/TC37 reference setup, see /4/ for technical details). X1201 is the designation used for
the SIM card holder in /4/.
GSM
engine
Molex card
holder
Figure 16: SIM card holder of DSB35 Support Box
Table 13 : Pin assignment of Molex SIM card holder on DSB35 Support Box
Pin no. Signal name I/O Function
1 CCVCC I Supply voltage for SIM card, generated by the GSM engine
2 CCRST I Chip card reset, prompted by the GSM engine
3 CCCLK I Chip card clock
4 CCGND - Individual ground line for the SIM card to improve EMC
5 CCVPP - Not connected
6 CCIO I/O Serial data line, bi-directional
7 CCDET1 - Connect to CCVCC
8 CCDET2 Connects to the CCIN input of the GSM engine. Serves to
recognize whether a SIM card is in the holder. Removing the SIM
card during operation will immediately stop further transmission of
signals to the card to protect the card from damage.
Pins 1 through 6 are the minimum requirement according to the GSM Recommendations,
while 7 and 8 are needed for the CCIN pin.
The X1202 switch is not mandatory, but may be added to help the system integrator control
the CCIN signal, e.g. for designing and testing purposes. When the switch is pushed open (3
is switched to 2), the line simulates an empty SIM card holder as if no SIM card was
inserted. When closed (3 switched to 1), the line simulates that the SIM card is present.