CLM920_AC3 Module Hardware Usage Guide
Shanghai Yuge Information Technology co., LTD
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3.5 USB interface
The CLM920 AC3 module USB interface supports USB2.0 high-speed protocol, supports
slave mode, and does not support USB charging mode. USB input and output traces must
comply with the USB2.0 feature. The USB interface is defined as follows
：
Table 3-10 USB interface pin definition
Pin number
Signal name
IO
Description
71
USB_VBUS
PI
USB insertion detection
70
USB_DM
IO
USB differential signal -
69
USB_DP
IO
USB differential
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 3-12 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. It is recommended to connect a 0 ohm resistor in series