Usb Application Without Usb Suspend Function - Quectel EG91 Series Hardware Design

 Execute AT+QSCLK=1commandto enable sleep mode.
 Ensure the DTR is held at high level or keep it open.
 The host's USB bus, which is connected with the module's USB interface, enters into suspended
state.
The following figure shows the connection between the module and the host.
 Sending data to EG91through USB will wake up the module.
 When EG91has a URC to report, RI signal will wake up the host.

3.5.1.4. USB Application without USB Suspend Function

If the host does not support USB suspend function, USB_VBUS should be disconnected with an
externalcontrol circuit to let the module enter into sleep mode.
 Execute AT+QSCLK=1commandto enable sleep mode.
 Ensure the DTR is held at high level or keep it open.
 Disconnect USB_VBUS.
The following figure shows the connection between the module and the host.
EG91_Hardware_Design
Figure 5: Sleep Mode Application with RI
Module
Power
USB_VBUS
Switch
USB_DP
USB_DM
RI
AP_READY
GND
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LTE Module Series
EG91 Hardware Design
Host
GPIO
VDD
USB_DP
USB_DM
EINT
GPIO
GND