Usb Interface - Quectel BG96 Manual

In order to enhance the reliability and availability of the (U)SIM card in applications, please follow the
criteria below in (U)SIM circuit design:

Keep the placement of (U)SIM card connector as close to the module as possible. Keep the trace
length as less than 200mm as possible.

Keep (U)SIM card signals away from RF and VBAT traces.

Assure the ground between the module and the (U)SIM card connector short and wide. Keep the
trace width of ground and USIM_VDD no less than 0.5mm to maintain the same electric potential.
Make sure the bypass capacitor between USIM_VDD and USIM_GND less than 1uF, and place it as
close to (U)SIM card connector as possible. If the system ground plane is complete, USIM_GND can
be connected to the system ground directly.

To avoid cross-talk between USIM_DATA and USIM_CLK, keep them away from each other and
shield them with surrounded ground. USIM_RST should also be ground shielded.

In order to offer good ESD protection, it is recommended to add a TVS diode array with parasitic
capacitance not exceeding 15pF. In order to facilitate debugging, it is recommended to reserve series
resistors for the (U)SIM signals of the module. The 33pF capacitors are used for filtering interference
of EGSM900. Please note that the (U)SIM peripheral circuit should be close to the (U)SIM card
connector.

The pull-up resistor on USIM_DATA line can improve anti-jamming capability when long layout trace
and sensitive occasion are applied, and should be placed close to the (U)SIM card connector.

3.9. USB Interface

BG96 contains one integrated Universal Serial Bus (USB) interface which complies with the USB 2.0
specification and supports high-speed (480Mbps) and full-speed (12Mbps) modes. The USB interface is
used for AT command communication, data transmission, software debugging and firmware upgrade. The
following table shows the pin definition of USB interface.
Table 10: Pin Definition of USB Interface
Pin Name Pin No.
USB_VBUS 8
USB_DP 9
USB_DM 10
GND 3
For more details about USB 2.0 specification, please visit http://www.usb.org/home.
BG96_Hardware_Design
I/O Description
AI USB connection detection
IO USB differential data bus (+)
IO USB differential data bus (-)
Ground
LPWA Module Series
BG96 Hardware Design
Comment
Typically 5.0V
Require differential
impedance of 90Ω
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