User's Manual

MC46 Hardware Interface Description
DRAFT
MC46_HD_V02.8xb Page 73 of 98 21.08.2003
Function Signal name IO Signal form and level Comments
VDD Low
Power
VDDLP I/O
R
I
=1kW
V
O
max # 4.0V (output)
V
I
min = 2.2V, V
I
max = 5.5V (input)
I
I
typ = 10µA at BATT+ = 0V
Mobile in POWER DOWN mode:
V
I
min = 1.2V
Supplies the RTC with
power via an external
capacitor or buffer battery
if no V
BATT+
is applied.
If unused keep pin open.
Ignition /IGT I
R
I
# 100kW, C
I
# 1nF
V
IL
max = 0.5V at Imax = -20µA
V
Open
max = 2.3V
ON
~~~
|____|
~~~
Active Low ³ 100ms
Input to switch the mobile
ON.
The line must be driven
low by an Open Drain or
Open Collector driver.
Emergency
shutdown
(Watchdog)
/EMERGOFF I
R
I
#22kW
V
IL
max = 0.5V at Imax = -100µA
V
Open
max = 2.73V
Signal
~~~
|______|
~~~
Active Low ³ 3.2s
Watchdog:
V
OL
max = 0.35V at I = 10µA
V
OH
min= 2.25V at I = -10µA
f
O
min = 0.16Hz
f
O
max = 1.55Hz
This line must be driven by
an Open Drain or Open
Collector driver.
Emergency shutdown
deactivates the power
supply to the module.
The module can be reset if
/IGT is activated after
emergency shutdown.
To switch the mobile off
use the AT^SMSO
command.
/EMERGOFF also
indicates the internal
watchdog function.
To avoid floating if pin is
high impedance, use pull-
down resistor tied to VDD.
See chapter 3.3.2.1.
If unused keep pin open.
V
OL
max = 0.2V at I = 1mA
V
OH
min = 2.35V at I = -1mA
V
OH
max = 2.73V
Synchroni-
zation
SYNC O
1 Tx, 877µs impulse each 4.616ms and
2 Tx, 1454µs impulse each 4.616ms, with
300µs forward time.
Indicates increased current
consumption during uplink
transmission burst. Note
that timing is different
during handover.
Alternatively used to
control status LED (see
Chapter 3.12.2.2).
If unused keep pin open.