Sunsea AIoT SIMCom SIM7075G User Manual page 30

SIM7075G User Manual V1.00
After setting the AT command "AT+CSCLK=0", SIM7075G will do nothing when the DTR pin is pulling up.
NOTE
For more details of AT commands about UART, please refer to document [1] and [20].
3.4 USB Interface
SIM7075G has a USB2.0 interface. It can be used for software upgrade and software debugging.
The USB of the SIM7075G only supports slave mode and does not support USB charging. USB does not
support Suspend mode, the module will not be able to enter the minimum power mode when USB is
connected.
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.
Figure 16: 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.
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