Usb Interface - Quectel BG95 A-GL Series Hardware Design

Ensure a short and wide ground trace between the module and the (U)SIM card connector. Keep

the ground and USIM_VDD traces at least 0.5 mm wide to maintain the same electric potential.
Make sure the bypass capacitor between USIM_VDD and USIM_GND is less than 1 μF, and place
it as close to the (U)SIM card connector as possible. If the system ground plane is complete,
USIM_GND can be directly connected to the system ground.
To avoid cross-talk between USIM_DATA and USIM_CLK, keep their traces away from each other

and shield them with ground. USIM_RST should also be shielded with ground.
To offer good ESD protection, it is recommended to add a TVS diode array with parasitic

capacitance not exceeding 15 pF. It is recommended to reserve 0 Ω series resistors for the (U)SIM
signals of the module to facilitate debugging. The 33 pF capacitors are used for filtering interference
of EGSM900. Note that the (U)SIM peripheral circuit should be close to the (U)SIM card connector.
The pull-up resistor on USIM_DATA trace can improve anti-jamming capability, and should be

placed close to the (U)SIM card connector.

4.2. USB Interface

The module features one integrated USB (Universal Serial Bus) interface that complies with the USB 2.0
specification and supports full speed mode only. This USB interface is used for AT command
communication, data transmission, software debugging and firmware upgrade*.
The USB interface pin definition is presented in the following table.
Table 15: USB Interface Pin Definition
Pin Name Pin No.
USB_VBUS 8
USB_DP 9
USB_DM 10
It is recommended to reserve test points for debugging and firmware
BG95xA-GL_Hardware_Design
I/O Description
AI USB connection detect
AIO USB differential data (+)
AIO USB differential data (-)
LPWA Module Series
Comment
Typ. 5.0 V
Compliant with the USB 2.0 standard
specification.
Requires differential impedance of 90 Ω.
upgrading* in your designs.
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