ETAS
Hardware Description
FETK-T1.1
-
User
Guide
22
4.4
Power Supply
The FETK-T1.1 requires a permanent power supply. It is typically powered
directly from the car battery. The input voltage may vary between 6.0
V and
36
V. In case of higher input voltages to the FETK, additional voltage protection
is required.
The FETK is suitable for 12
V and 24
V systems. In 24
V systems the low dump
capability is reduced.
The FETK-T1.1 will also accept voltage drops down to 3
V, for a maximum
duration of 15
ms (for additional details of low voltage operation, see ISO stan
-
dard 16750).
From the input battery voltage, switch-mode power supplies provide all neces
-
sary voltages on the FETK-T1.1. The power supply of the ECU is not affected by
the FETK-T1.1. An automatic switch ensures that the power supply of the
FETK-T1.1 is automatically switched on and off when the FETK enters and
leaves its standby (sleep) mode.
The FETK-T1.1 is supplied with power through the connector CON4.
Fig.
4
-
4
Location of the Power Supply Connector (CON4)
4.5
ECU Voltage Supervisor
The ECU voltage (VDDP) is monitored by the FETK to recognize whether the
ECU is switched on or off. The Pin "VDDSBRAM" is used to provide the standby
voltage and to monitor it. It's not possible to monitor VDDSBFRAM, only.
The FETK-T1.1 monitors the VDDSBRAM supply on board the FETK. The micro
-
controller’s standby power supply pin must be connected to the FETK pin
VDDSBRAM.
NOTE
The FETK-T1.1 only allows switching between reference page and working
page if there is a valid voltage at the sense pin and the working page has been
initialized by the calibration and development system.
CON4