Quectel BC660K-GL, Руководство пользователя

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NB-IoT Module Series
BC660K-GL Hardware Design
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A reference design for the USIM interface with a 6-pin USIM card connector is below.
Module
USIM_VDD
USIM_GND
USIM_RST
USIM_CLK
USIM_DATA
22
Ω
22
Ω
22
Ω
100 nF
USIM Card Connector
GND
TVS
33 pF 33 pF 33 pF
VCC
RST
CLK IO
VPP
GND
GND
33 pF
10 k
Ω
Figure 16: Reference Design for USIM Interface with a 6-pin USIM Card Connector
To enhance the reliability and availability of the USIM card in applications, follow the criteria below in
USIM circuit design:
⚫
Place the USIM card connector as close to the module as possible and keep the trace length as less
than 200 mm as possible.
⚫
Keep USIM card signal lines away from RF and VBAT traces.
⚫
Make the trace between the ground of the module and that of the USIM card connector short and
wide and ensure the trace width no less than 0.5 mm avoid any decrease in electric potential. The
decoupling capacitor between USIM_VDD and GND should be not more than 1
μF and be placed
close to the USIM card connector.
⚫
To avoid cross-talk between USIM_DATA and USIM_CLK, keep them away from each other and
shield them separately with surrounding ground.
⚫
To offer good ESD protection, it is recommended to add a TVS diode array whose parasitic
capacitance should be not more than 50 pF. Place the ESD protection device as close to the USIM
card connector as possible, and ensure the USIM card signal lines from the USIM card connector go
through the ESD protection device before reaching the module. The 22
Ω resistors should be
Maximum supply current: about 80 mA.
USIM_CLK 13 USIM card clock
USIM_RST 12 USIM card reset
USIM_DATA 11 USIM card data
USIM_GND 10 Dedicated ground for USIM card