HUAWEI MU739 HSPA+ LGA Module
Hardware Guide
Description of the Application Interfaces
Issue 01 (2011-08-24)
Huawei Proprietary and Confidential
Copyright © Huawei Technologies Co., Ltd.
32
Figure 3-16
Pin definition of USIM Socket
pin1
SIM_VCC
pin2
SIM_RST
pin3
SIM_CLK
pin4
GND
pin5
NULL
pin6
SIM_DATA
To meet the requirements of 3GPP TS 51.010-1 protocols and electromagnetic
compatibility (EMC) authentication, the USIM card socket should be placed near
the LGA interface (it is recommended that the PCB circuit connecting the LGA
interface and the USIM card socket not exceed 100 mm), because a long circuit
may lead to wave distortion, thus affecting signal quality.
It is recommended that you wrap the area adjacent to the SIM_CLK and
SIM_DATA signal wires with a ground wire. The GND pin of the USIM card socket
and the GND pin of the USIM card must be well connected to the power GND pin
supplying power to the MU739 module.
A 100 nF capacitor (0402 package is recommended so that larger capacitance
such as 1 uFcan be employed if necessary) and a 33 pF capacitor are placed
between the SIM_VCC and GND pins in a parallel manner. Three 33 pF capacitors
are placed between the SIM_DATA and GND pins, the SIM_RST and GND pins,
and the SIM_CLK and GND pins in parallel to filter interference from RF signals.
You need to use a 4.7
KΩ
resistor pulling the SIM_DATA pin up.
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