User's Manual

UE910 3G HARDWARE USER GUIDE 1vv0301171 Rev.3 • 2015-04-17 38 of 78

In the following flow chart is detailed the proper restart procedure:

NOTE:

Do not use any pull up resistor on the HW_SHUTDOWN* line nor any totem

pole digital output. Using pull up resistor may bring to latch up problems on the

UE910 power regulator and improper functioning of the module.

To proper power on again the module please refer to the related paragraph

(“Power ON”)

The unconditional hardware shutdown must always be implemented on the

boards and should be used only as an emergency exit procedure.

“HW SHUTDOWN

Unconditional”

START

HW_SHUTDOWN* = LOW

Delay = 200ms

PWRMON = ON

Disconnect

VBATT

“HW SHUTDOWN

Unconditional”

END

HW_SHUTDOWN* = HIGH

Delay = 1s