TLE9260-3QX Datasheet, PDF (91/175 Pages) Infineon Technologies AG – Dedicated Data Sheets are available for the different product variants

12
Fail Outputs
12.1
Block and Functional Description
TLE9260-3QX
Fail Outputs
Failure logic
FO1/2
SBC Init
Mode
5 V_ int
T _test
RTEST
T _{FO_PL}
Failure Logic
FO3/TEST
Figure 36 Simplified Fail Output Block Diagram for FO1/2 and for FO3/TEST
The fail outputs consist of a failure logic block and three open-drain outputs (FO1, FO2, FO3) with active-low
signalization.
The fail outputs are activated due to following failure conditions:
• Watchdog trigger failure (For config 3&4 only after the 2nd watchdog trigger failure and for config 1&2 after 1st
watchdog trigger failure)
• Thermal shutdown TSD2
• VCC1 short to GND
• VCC1 over voltage (only if the SPI bit VCC1_OV_RST is set)
• After 4 consecutive VCC1 under voltage event (see Chapter 13.6 for details)
At the same time SBC Fail-Safe Mode is entered (exceptions are watchdog trigger failures depending on selected
configurations - see Chapter 5.1.1).
The fail output activation is signalled in the SPI bit FAILURE of the register DEV_STAT.
For testing purposes only the Fail Outputs can also be activated via SPI by setting the bit FO_ON. This bit is
independent of the FO failure bits. In case that there is no failure condition, the FO outputs can also be turned off
again via SPI, i.e. no successful watchdog trigger is needed.
The entry of SBC Fail-Safe Mode due to a watchdog failure can be configured as described in Chapter 5.1.1.
In order to deactivate the fail outputs in SBC Normal Mode the failure conditions must not be present anymore
(e.g. TSD2, VCC1 short circuit, etc) and the bit FAILURE needs to be cleared via SPI command. In case of a
FAILURE bit setting due to a watchdog fail, a successful WD trigger is needed in addition, i.e. WD_FAIL must be
cleared. WD_FAIL will also be cleared when going to SBC Sleep or SBC Fail-Safe Mode due to another failure
(not a WD failure) or if the watchdog is disabled in SBC Stop Mode.
Note: The Fail output pin is triggered for any of the above described failures. No FAILURE is caused for the 1st
watchdog failure if selected for Config2.
The three fail outputs are activated simultaneously with following output functionalities:
• FO1: Static fail output
• FO2: 1.25Hz, 50% (typ.) duty cycle, e.g. to generate an indicator signal
Data Sheet
91
Rev. 1.1, 2014-09-26