
Reproduction forbidden without Fibocom Wireless Inc. written authorization - All Rights Reserved.
L850-GL Hardware User Manual Page 33 of 54
Figure 3-13 Length Match Design of PCIe Difference Pair
3.4.2 USB Interface
The L850 module supports USB2.0 which is compatible with USB High-Speed (480 Mbit/s) and USB
Full-Speed (12 Mbit/s).It supports USB3.0 using for LTE cat9 high speed data throughput at the same
time. For the USB timing and electrical specification of L850 module, please refer to Universal Serial Bus
Specification 2.0” and “Universal Serial Bus Specification 3.0”.
When module inserted PC, USB can enumerate three ACM and three NCM ports in Android/Linux system,
the ports can be configured in practical application.
3.4.2.1 USB Interface Definition
Pin#
Pin Name
I/O
Description
Type
7
USB_D+
I/O
USB Data Plus
0.3---3V,
USB2.0
9
USB_D-
I/O
USB Data Minus
0.3---3V,
USB2.0
29
USB3.0_TX-
O
USB3.0 Transmit data minus
-
31
USB3.0_TX+
O
USB3.0 Transmit data plus
-
35
USB3.0_RX-
I
USB3.0 receive data minus
-
37
USB3.0_RX+
I
USB3.0 receive data plus
-
3.4.2.2 USB2.0 Interface Application
The reference circuit is shown in Figure 3-14: