Product Info

Smart LTE Module Series
SC650T Hardware Design
SC650T_Hardware_Design 49 / 131
important to route the USB differential traces in inner-layer with ground shielding on not only upper
and lower layers but also right and left sides.
 Keep the ESD protection devices as close as possible to the USB connector.
 Make sure the trace length difference between USB 2.0 DM/DP differential pair and that between
USB 3.0 RX/TX differential pairs both do not exceed 0.7mm.
Table 9: USB Trace Length Inside the Module
Pin No.
Signal
Length (mm)
Length Difference (DP-DM)
33
USB_DM
40.02
-0.04
32
USB_DP
39.99
171
USB_SS_RX_P
27.89
0.01
172
USB_SS_RX_M
27.90
174
USB_SS_TX_P
21.51
0.91
175
USB_SS_TX_M
22.42
3.10. UART Interfaces
The module provides the following four UART interfaces:
 UART5: 4-wire UART interface, hardware flow control supported, 1.8V power domain
 UART6: 2-wire UART interface,
 UART2: 2-wire UART interface, used for debugging
 UART4: 2-wire UART interface
The following table shows the pin definition of UART interfaces.
Table 10: Pin Definition of UART Interfaces
Pin Name
Pin No.
I/O
Description
Comment
UART2_TXD
5
DO
UART2 transmit data.
Debug port by default.
1.8V power domain.
If unused, keep these pins
open.
UART2_RXD
6
DI
UART2 receive data.
Debug port by default.