ETAS
Hardware Description
ETK-T2.2 User Guide
24
unplugged. In addition, the ETK-T2.2 senses the status of the /HDRST line to
generate a write protect signal for its memory. Finally, the ETK-T2.2 generates
a reset signal by pulling /PORST to keep the ECU in reset while the ETK is in
power save mode and to prevent the microcontroller from starting until the ETK
is ready to work. The ETK is ready to work when it has finished its initialization
after leaving power save mode or after initial power-up. This feature allows it
also to reset the ECU under tool control (required for INCA and ProF) and to
perform an emergency stop of the ECU in case of ETK failure.
4.11
Power Supply
The ETK-T2.2 needs a permanent power supply. It is powered directly from the
car battery. The input voltage may vary between 4.3
V and 18
V.
The ECU voltage (U
SG
) is monitored by the ETK to recognize whether the ECU
is switched on or off. In case of higher input voltages to the ETK an additional
voltage converter is required. All necessary voltages are created through
switching power supplies which minimizes heat build-up. The power supply of
the ECU is not affected by the ETK-T2.2. An automatic switch ensures that the
power supply of the ETK-T2.2 is automatically switched on and off.
Fig.
4
-
6
Power Supply Connectors CON2 and CON3
The ETK-T2.2 can be supplied with power through the 2-pin power supply con
-
nector CON2. Additionally the through-hole solder pad CON3 can be used to
connect a power supply U
Batt2
. The power supply on CON3 must use the GND
of CON2.
Fig.
4
-
7
Power Supply Connector CON2
CON2
CON3
CON2
CON4
CON1
CON5