User's Manual

H380 M.2 Series Module Hardware User Manual page
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5.4 USB Interface
5.4.1 USB Interface definition
Pin No Pin Name I/O Description
7 USB_DP I/O USB differential Data (+)
9 USB_DM I/O USB differential Data (-)
H380 wireless communication module supports USB 2.0. It should install USB driver before use on
PC. After H380 module plugged into the PC, the USB can enumerate seven ports:
 One 3G Modem/AT port for data transmission
 Three ports for sending AT Command

One port for trace LOG information
 Two ports reserved currently.
5.4.2 USB Interface Application
Reference Design as follow:
Figure 5- 6 USB Interface Reference Design
The capacitor of TVS(T101 and T102) must be less than 1pF. VUSB power supply has been
connected internal, so the VBUS pin of HOST can float.USB_D+ and USB_D- are high speed differential
serial signals, the highest transmit speed is up to 480 Mbps.
PCB Layout note:
 USB_D+ and USB_D- signals trace same length, parallel, as short as possible.

USB_D+ and USB_D- should be isolated by Ground in same and adjacent layer. It is better for USB
performance when adding more GND VIA.
 USB2.0 signal should trace near the Ground layer of PCB.

Impedance control of USB differential signals is 90 ohm.
 USB signal should keep away from any strong noise signal like power supply etc.