User's Manual

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H380-GL Hardware User Manual Page
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system switching.
 MBIM interface is used for initiating data service;

For 7 ACM ports:
1 port is 3G Modem/AT port, which is mainly used for initiating data service
3 ports are used for sending AT Command
1 port is used for capturing software LOG information
2 ports are reserved for future use
3.4.1 USB Interface Definition
Pin
Pin Name
I/O
Reset Value
Pin Description
Type
7
USB_D+
I/O
USB Data Plus
0.3---3V,
USB2.0
9
USB_D-
I/O
USB Data Minus
0.3---3V,
USB2.0
3.4.2 USB2.0 Interface Application
The reference circuit is shown in Figure 3-11:
Figure 3- 11 Reference Circuit for USB2.0 Interface
The module supports USB 2.0 High-Speed, so the TVS equivalent capacitance on USB_D-/D+ differential
signal line shall be lower than 1pF, it’s recommended to adopt TVS with 0.5pF capacitance.
USB_D- and USB_D + are high-speed differential signal lines, the maximum transmission rate is up to
480 Mbits/s, the PCB Layout shall strictly adhere to the following rules:

USB_D- and USB_D+ signal line controls 90 Ω differential impedance;

USB_D- and USB_D+ signal line shall be isometric and parallel, rectangular wiring shall be
avoided;

The cabling of USB_D- and USB_D+ signal line shall be located on the signal layer closest to the
ground, up, down, left and right grounding protections shall be completed for wiring.