Functional Description
Page 44
3.1.1
Ignition
You can use the ignition pin to control the start-up and shut-down of the BL51E without
having to disconnect the power supply.
To use the ignition function, connect pin IGNITIONCON (KL15) to the power input pin
POWERCON_IN (KL30) via a switch or a controller.
Figure 7.
Connection of power pins from PSU
Ignition Behavior
When the power input supply voltage is present and the ignition is turned on (volt-
age higher than 5.3 V), the 12 V supply voltage inside the system is also switched on
(see figure below).
When the ignition is turned off (voltage lower than 0.8 V), a power button event is
generated.
Shut-down with or without delay:
-
The input voltage is not switched off at once but can be supplied for a user-
defined time (shut-down delay) so that the operating system of the BL51E
can shut down in a controlled way.
-
The ignition pin can also be permanently connected to the power input pin.
In this case the BL51E will start up as soon as the supply voltage is con-
nected and switch off as soon as the supply voltage is disconnected without
a delay for shutting down the operating system.
The behavior (e.g., reboot, shut down) can be set in the operating system.
Figure 8.
Ignition behavior
DC/DC
Converter
CPU
12V
Box PC
Ignition
(IGNITIONCON, KL15)
Power Input
(POWERCON_IN, KL30)
GND
(POWERCON_GND, KL31)
Power input supply voltage
(must be present)
Ignition
12 V
Definable shut
‐
down delay
