Specifications

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SIM7080G _Hardware Design _V1.03 30 2019-12-13

3.4 USB Interface

SIM7080G has a USB2.0 interface, it can be used for software upgrade and software debugging.

USB_VBUS is the detecting signal for USB inserting. The input voltage range on the USB_VBUS

pin is from 3.5V to 5.25V. If there is out of this range, it may be due to USB function

unidentifiable, even damaging the module.

The reference circuit refers to the following figure.

USB_ VBUS

USB_DM

USB_DP

GND

USB

VBUS

D-

D+

GND

D2D1

0Ω

USB_ID

MODULE HOST

Figure 15: USB reference circuit

Because of the high speed on USB bus, more attention should be paid to the influence of the

junction capacitance of the ESD component on USB data lines. Typically, the capacitance of the D1

and D2 should be less than 3pF.

D3 is suggested to select the diode with anti-ESD and voltage surge function, or customer could

add a ZENER diode for surge clamping.

Note

：

The USB_DM and USB_DP nets must be traced by 90Ohm+/-10% differential

impedance.