Product Info

LTE Module Series
EG91 Hardware Design
EG91_Hardware_Design 33 / 93
 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.
Figure 5: Sleep Mode Application with RI
 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.
USB_VBUS
USB_DP
USB_DM
AP_READY
VDD
USB_DP
USB_DM
GPIO
Module Host
RI EINT
Power
Switch
GPIO
GND
GND