Siemens XT65, Hardware Overview, Page: 35 / 58

XT65/XT75 Hardware Interface Overview
6.5 Pin Assignment and Signal Description
s
XT65_XT75_HO_v00.130 Page 35 of 67 2006-10-12
Confidential / Preliminary
Power
indicator
PWR_IND O V
IH
max = 10V
V
OL
max = 0.4V at Imax = 2mA
PWR_IND (Power Indicator) noti-
fies the module’s on/off state.
PWR_IND is an open collector
that needs to be connected to an
external pull-up resistor. Low state
of the open collector indicates that
the module is on. Vice versa, high
level notifies the Power-down
mode.
Therefore, the pin may be used to
enable external voltage regulators
which supply an external logic for
communication with the module,
e.g. level converters.
Ignition IGT I Internal pull-up: R
I
≈ 30k Ω , C
I
≈ 10nF
V
IL
max = 0.8V at Imax = -150µA
V
OH
max = V
BATT+
ON
~~~
|____|
~~~
Active Low
≥
300ms
This signal switches the mobile
on.
This line must be driven low by an
open drain or open collector
driver.
Emer-
gency
reset
EMERG_RST I Internal pull-up: R
I
≈ 5k Ω
V
IL
max = 0.2V at Imax = -0.5mA
V
OH
min = 1.75V
V
OH
max = 3.05V
Signal
~~~
|______|
~~~
Pull down
≥
10ms
Reset or shut down in case of
emergency: Pull down and release
EMERG_RST. Then, activating
IGT for 400ms will reset XT65/
XT75. If IGT is not activated for
400ms, XT65/XT75 switches off.
Data stored in the volatile memory
will be lost. For orderly software
controlled reset rather use the
AT+CFUN command (e.g.
AT+CFUN=x,1).
This line must be driven by open
drain or open collector.
If unused keep pin open.
Power-on
reset
O Internal pull-up: R
I
≈ 5k Ω
V
OL
max = 0.2V at I = 2mA
V
OH
min = 1.75V
V
OH
max = 3.05V
Reset signal driven by the module:
Reset signal driven by the module
which can be used to reset any
application or device connected to
the module. Only effective for
120ms during the assertion of IGT
when the module is about to start.
Table 17:
Signal description
Function Signal name IO Signal form and level Comment
VEXT
EMRG_RST
appr. 120ms