CLM920 TD3 LTE Module Hardware Usage Guide
Shanghai Yuge Information Technology co., LTD
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The module acts as a USB slave device and supports USB sleep and wake-up
mechanisms. USB interface application reference circuit is as follows
：
Figure 3-11 USB connection design circuit diagram
The USB interface supports high-speed (480Mbps) and full-speed (12Mbps) modes.
Therefore, the trace design needs to strictly follow the USB2.0 protocol requirements.
Pay attention to the protection of the data lines, differential traces, and control impedance
of 90
Ω
.
In order to improve the antistatic performance of the USB interface, it is recommended to
add an ESD protection device on the data line. The equivalent capacitance of the
protection device is less than 2pF.
The USB interface bus supply voltage is provided internally by the module and is not
required externally. At the same time, since the USB interface of the module does not
provide USB bus power, the module can only be used as a slave device of the USB bus
device.
The USB interface can support functions such as software download upgrade, data
communication, AT Command, GNSS NMEA output and other functions.
