Figure 26: Test Points Of Firmware Upgrade - Quectel UG95 Hardware Design

In order to ensure the USB interface design corresponding with the USB 2.0 specification, please comply
with the following principles:

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.

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 not only upper and
lower layer but also right and left side.

Keep the ESD components as close as possible to the USB connector.

It is suggested that a RC circuit should be reserved near USB connector for debug.
The USB interface is recommended to be reserved for firmware upgrade in your design. The following
figure shows the recommended test points.
NOTES
1. UG95 module can only be used as a slave device.
2. It is suggested that you should set USB_DP, USB_DM and USB_VBUS pins as test points and then
place these test points on the DTE for debug.
3. USB interface supports software debug and firmware upgrade by default.
UG95_Hardware_Design
Module
USB_VBUS
USB_DM
USB_DP
VBAT_BB
VBAT_RF
PWRKEY
GND

Figure 26: Test Points of Firmware Upgrade

Confidential / Released
UMTS/HSPA Module Series
UG95 Hardware Design
Connector
USB_VBUS
USB_DM
USB_DP
VBAT
PWRKEY
GND
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