User's Manual

Table Of Contents
UMTS/HSPA Module Series
UG96 Hardware Design
UG96_Hardware_Design Confidential / Released 33 / 75
3.7.2.2. Emergency Shutdown
The module can be shut down by the pin PWRDWN_N. It should only be used under emergent situation.
The following table shows the pin definition of PWRDWN_N.
Table 8: PWRDWN_N Pin Description
Pin Name
Pin No.
Description
DC Characteristics
Comment
PWRDWN_N
16
Turn off the module
V
IH
max=2.1V
V
IH
min=1.3V
V
IL
max=0.5V
Pull-up to VRTC
internally with 4.7
resistor.
Driving the PWRDWN_N to a low level voltage at least 100ms, the module will execute power-down
procedure after PWRDWN_N is released. It is recommended to use an open drain/collector driver to
control the PWRDWN_N. The level of STATUS pin is low after UG96 is turned off. A simple reference
circuit is illustrated in the following figure.
Turn off pulse
PWRDWN_N
4.7K
47K
100ms
Figure 13: Turn off the Module Using Driving Circuit
The other way to control the PWRDWN_N is using a button directly. A TVS component is indispensable to
be placed nearby the button for ESD protection. When pressing the key, electrostatic strike may generate
from finger. A reference circuit is shown in the following figure.