
LPWA Module Series
BG952A-GL_QuecOpen_Hardware_Design
38 / 72
3.12. USB Interface
*
BG952A-GL QuecOpen provides one integrated Universal Serial Bus (USB) interface which complies
with the USB 2.0 specification and supports full speed mode only.
The following table shows the pin definition of USB interface.
Table 14: Pin Definition of USB Interface
Pin Name
Pin No. I/O
Description
Comment
USB_VBUS
8
AI
USB connection detect
Typical 5.0 V
USB_DP
9
AIO
USB differential data (+)
Require differential impedance of 90 Ω
USB_DM
10
AIO
USB differential data (-)
For more details about USB 2.0 specification, visit http://www.usb.org/home.
It is recommended to reserve test points for debugging and firmware upgrading
*
in your designs.
Figure 16: Reference Design of USB Interface
To ensure USB data signal integrity, if possible, reserve a 0 Ω resistor on USB_DP and USB_DM traces,
respectively. Resistors R1 and R2 should be placed close to the module and to each other. The extra
trace stubs must be as short as possible.
To meet USB 2.0 specification, comply with the following principles while designing the USB interface.
It is important to route the USB signal traces as differential pairs with ground surrounded. The
impedance of USB differential trace is 90 Ω.