LTE Standard Module Series
EC200U_Series_Hardware_Design 57 / 94
MODULE
USB_BOO T
VDD_EXT
4. 7K
Test points
TVS
Close to test points
GND
2
1
3
USB_BOOT
MODULE
KEYOUT0
TVS
TVS
S1
Close to test points
Figure 28: Reference Circuit of USB_BOOT Interface
Please make sure that VBAT is stable before PWRKEY is pulled down. It is recommended that the time
interval between powering up VBAT and pulling down PWRKEY is no less than 30 ms.
NOTE