Emc And Esd Features - Huawei MU709 Series Hardware Manual

HUAWEI MU709 Series HSPA+ Mini PCIe Module
Hardware Guide
Item
ESD with DVK (or
embedded in the
host)
Groups ≥ 2

5.6 EMC and ESD Features

The following are the EMC design comments:

Attention should be paid to static control in the manufacture, assembly, packaging,
handling, storage process to reduce electrostatic damage to HUAWEI module.

RSE (Radiated Spurious Emission) may exceed the limit defined by EN301489 if
the antenna port is protected by TVS (Transient Voltage Suppressor), which is
resolved by making some adjustment on RF match circuit.

TVS should be added on the USB port for ESD protection, and the parasitic
capacitance of TVS on D+/D- signal should be less than 2 pF. Common-mode
inductor should be added in parallel on D+/D- signal.

TVS should be added on the USIM interface for ESD protection. The parasitic
capacitance of TVS on USIM signal should be less than 10 pF.

Resistors in parallel and a 10 nF capacitor should be added on RESIN_N signal
to avoid shaking, and the distance between the capacitor and the related pin
should be less than 100 mil.

PCB routing should be V-type rather than T-type for TVS.

An integrated ground plane is necessary for EMC design.
The following are the requirements of ESD

The electrostatic discharge protected area (EPA) must have an ESD floor whose
surface resistance and system resistance are greater than 1 x 10
than 1 x 10

The EPA must have a sound ground system without loose ground wires, and the
ground resistance must be less than 4 Ω.

The workbench for handling ESD sensitive components must be equipped with
common ground points, the wrist strap jack, and ESD pad. The resistance
between the jack and common ground point must be less than 4 Ω. The surface
resistance and system resistance of the ESD pad must be less than 1 x 10
Test Condition
 Contact and Air
discharges: 10
positive and 10
negative applied
 Contact Voltage: ±2
kV, ±4 kV
 Air Voltage : ±2 kV, ±4
kV, ±8 kV

Operation mode:
working with service
connected
Ω.
9
Huawei Proprietary and Confidential
Copyright © Huawei Technologies Co., Ltd
Issue 04 (2015-06-25)
Electrical and Reliability Features
Standard Sample size
IEC61000 2 pcs
-4-2
environment control:
Results
Visual inspection: ok
Function test: ok
RF specification: ok
Ω while less
4
Ω.
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