Huawei MU509-65 HSDPA Hardware Manual page 38

HUAWEI MU509-65 HSDPA LGA Module
Hardware Guide
Figure 3-20 Circuit of the USIM card interface

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 USIM_CLK and
USIM_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 MU509-65 module.
A 2.2 μF capacitor and a 33 pF capacitor are placed between the USIM_VCC and

GND pins in a parallel manner. Three 33 pF capacitors are placed between the
USIM_DATA and GND pins, the USIM_RESET and GND pins, and the USIM_CLK
and GND pins in parallel to filter interference from RF signals.
You do not need to pull the USIM_DATA pin up during design as a 20000 Ω resistor

is used to connect the USIM_DATA pin to the USIM_VCC pin.
 It is recommended to take electrostatic discharge (ESD) protection measures near
the USIM card socket. The TVS diode with Vrwm of 5 V and junction capacitance
less than 10 pF must be placed as close as possible to the USIM socket, and the
Ground pin of the ESD protection component is well connected to the power
Ground pin that supplies power to the MU509-65 module.
Issue 01 (2016-04-08)
Huawei Proprietary and Confidential
Copyright © Huawei Technologies Co., Ltd.
Description of the Application Interfaces
2.2
38