Product Info

LTE Module Series
BG96 Hardware Design
BG96_Hardware_Design 46 / 81
added in series between the module and the test points so as to facilitate debugging, and the resistors are
not mounted by default. In order to ensure the integrity of USB data line signal, L1/R3/R4 components
must be placed close to the module, and also these resistors should be placed close to each other. The
extra stubs of trace must be as short as possible.
The following principles should be complied with when design the USB interface, so as to meet USB 2.0
specification.
 It is important to route the USB signal traces as differential pairs with total grounding. The impedance
of USB differential trace is 90Ω.
 Do not route signal traces under crystals, oscillators, magnetic devices and RF signal traces. It is
important to route the USB differential traces in inner-layer with ground shielding onnot only upper
and lower layers but also right and left sides.
 Pay attention to the influence of junction capacitance of ESD protection components on USB data
lines. Typically, the capacitance value should be less than 2pF.
 Keep the ESD protection componentsas close to the USB connector as possible.
BG96 module can only be used as a slave device.
3.10. UART Interfaces
The module provides threeUART interfaces: UART1,UART2 and UART3interfaces. The following are
theirfeatures.
 UART1 interface supports
9600bps,19200bps,38400bps,57600bps,115200bps,230400bps,460800bps and921600bpsbaud
rates, and the default is 115200bps. Itis used for data transmission and AT command
communication.
 UART2 interface supports 115200bpsbaud rate, and is used formodule debugging and log output.
 UART3interface supports 115200bps baud rate, and is used for outputting GNSS dataandNMEA
sentences.
The following tables show the pin definition of the three UART interfaces.
NOTE