Huawei Technologies Co. Ltd UM01-HW Manuel D’Utilisation
MC703 CDMA EV-DO Wireless Module V100R001
Product Description
Issue 1.00 (2009-9-10)
Huawei Proprietary and Confidential
Page 29 of 40
Figure 4-3 Circuits of the USIM card interface
Figure 4-4 Sequence of the pins of the USIM card
Figure 4-5 Sequence of the pins of a USIM card seat
The typical rate of the USIM card interface is about 3.25 MHz. Therefore, the USIM card seat
should be as close to the module interface as possible and the line should not exceed 10 cm.
This prevents the communications quality of signals from being affected by serious waveform
distortion because of too long lines. Ground lines should be used to enclose the lines used for
transmitting USIM_CLK signals and USIM_IO signals.
should be as close to the module interface as possible and the line should not exceed 10 cm.
This prevents the communications quality of signals from being affected by serious waveform
distortion because of too long lines. Ground lines should be used to enclose the lines used for
transmitting USIM_CLK signals and USIM_IO signals.
To filter out the interference from antenna signals, you need to add a 0.1 µF or a 0.22 µF
capacitor to the USIM_VCC signal and a 33 pF capacitor to the USIM_CLK, USIM_IO, and
USIM_RST signals based on the GND network. In addition, you need to add TVS diodes to
capacitor to the USIM_VCC signal and a 33 pF capacitor to the USIM_CLK, USIM_IO, and
USIM_RST signals based on the GND network. In addition, you need to add TVS diodes to