User's Manual

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add a resistor with value below 10Ω to the DM and DP in USB interface to ensure correct transmission for USB
data. Just like the resistors R408 and R409 in Figure 2-7.
3) To avoid static electricity in USB interface, it is recommended to use the ESD protection device. Just like the
varistor RV406, RV407 and RV408 with capacitor values below 3pF.
4) To ensure USB working reliably, it is recommended to use additional protection device.
Figure 2-7 The reference circuit of USB interface
2.2.4 USIM interface
U6100 supports USIM card in UMTS mode as well as SIM card in GSM/GPRS/EDGE mode.
2.2.4.1 Description
U6100 provides USIM card interface by 60PIN board to board connector which can be used in both UMTS and
GSM/GPRS/EDGE networks. The Table 2-6 gives more detail information.
Table 2-6 U6100 USIM card interface description
Signals of
USIM interface
Pins of 60Pin
board to board connector
SN. of 60Pin
board to board connector
Description
DATA USIM_DATA 20 USIM card data
CLK USIM_CLK 38 USIM card CLK