Hardware Development Guide
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ME3630 mini-PCIE
ME3630 mini-PCIE
Figure 4–11
USIM_DET pin logic
4.11
USB
I
NTERFACE
The module has a high-speed USB2.0 interface, which supports both the full-speed (12 Mbps) mode and the high-speed (480 Mbps)
mode. It is connected to the system board side by the PIN 36 (USD_DM) and 38 (USB_DP). The USB interface is the path for
communication between the host and module and it is mainly used in data transmission.
Table 4-9 Definition and Description of USB Interface
Name
Pin
Description
USB_DM
36
USB data negative
USB_DP
38
USB data positive
The USB interface complies with the USB2.0 specifications and the electric features. When designing the host device, careful PCB
layout practices must be followed. USB_DP, USB_DM should be wired strictly according to the differential mode, and the length
difference between the two cables should be restricted within 1mm.
It is important to route the USB signal traces as differential pairs with total grounding. The impedance of USB differential trace is
90ohm.
Pay attention to the influence of junction capacitance of ESD component on USB data lines. Typically, the capacitance value should
be less than 2pF.