Usb Application Without Suspend Function - Quectel UC20 Manual

When the processor's USB bus returns to resume state, the module will be woken up.

3.5.1.3. USB Application without Suspend Function

If application processor communicates with module via USB interface, and processor does not support
USB suspend function, you should disconnect USB_VBUS with additional control circuit to let the module
enter into sleep mode.
 Execute AT command AT+QSCLK=1 to enable the sleep mode.
Disconnect USB_VBUS.

The following figure shows the connection between the module and application processor.
UC20_Hardware_Design
Module
USB_VBUS
USB_DP
USB_DM
AP_READY
RI
GND
Figure 4: USB Application with Suspend Function
Confidential / Released
UMTS/HSPA Module Series
UC20 Hardware Design
Processor
VDD
USB_DP
USB_DM
GPIO
EINT
GND
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