CLM920 TD3 LTE Module Hardware Usage Guide
Shanghai Yuge Information Technology co., LTD
- 73 -
The power-on time of any interface of the module must not be earlier than the boot time
of the module, otherwise the module may be abnormal or damaged.
5.5 Electrostatic property
There is no overvoltage protection inside the CLM920 TD3 module. The ESD protection
is required when the module is used to ensure product quality.
EMC design recommendations:
The USB port needs to add TVS on VDD, D+, D- for protection, and the TVS
parasitic capacitance on D+/D- is <2pF;
The module's USIM card external pin needs to be protected by TVS, and the parasitic
capacitance requirement is <10pF.
At the module input power supply, increase the TVS. It is recommended that the
clamp voltage VCL (Clamping Voltage) is less than 12V and the peak power PPP (Peak Pulse
Power) is not less than 100W.
The PCB layout of the protective device should be as close as possible to the "V" line
to avoid the "T" line.
The ground plane around the module guarantees integrity and should not be split.
ESD control of the surrounding environment and operators is required during module
production, assembly and laboratory testing.
Table 5-4 CLM920 TD3 ESD Features
Test port
Contact discharge Air discharge
unit
USB interface
±
4
±
8
KV
USIM interface
±
4
±
8
KV
Analog voice interface
±
4
±
8
KV
VBAT power supply
±
4
±
8
KV
5.6 Reliability index
Table 5-5 CLM920 TD3 reliability test
Test items
Test Conditions
Guideline Test Results
Low
temperatur
e work
Temperature:
–
40
℃
Working mode: normal work
Test duration: 24h
IEC6006
8-2-1
Visual inspection: normal
Function check: normal
RF indicator check: normal
High
Temperature: 85
℃
JESD22- Visual inspection: normal