TLE8108EM Datasheet, PDF (18/30 Pages) Infineon Technologies AG – Smart 8-Channel Low Side Relay Driver with SPI Interface

TLE 8108 EM
Smart 8-Channel Low Side Switch
Diagnosis Features
7
Diagnosis Features
The SPI of TLE8108EM provides diagnosis information about the device and about the load. The following
diagnosis states are implemented:
• Short circuit to battery (SCB): Can be detected if stages are turned on
• Short circuit to ground (SCG): Can be detected if stages are turned off (channel either in OFF or in input mode
with the dedicated input low)
• Open load (OL): Can be detected if stages are turned off (channel either in OFF or in input mode with dedicated
input low)
• Diagnosis of Overtemperature (DOT): Is set in case the thermal shut down temperature T_j(SC) is reached, if the
output is turned on (either ON-state or input mode and channel turned on via parallel INx). In case the thermal
shut down temperature T_j(SC) is reached during clamping in OFF state, DOT is set and the dedicated channel
can only be switched on again after a Clear mode is programmed, the temperature got below the shut down
threshold and the clamping has vanished. In case the thermal shut down temperature T_j(SC) is reached in OFF
state without clamping, there is no diagnosis entry and the channel can be switched on again after the thermal
shut down temperature T_j(SC) falls below the threshold.
In Clear mode (CLR) there is no diagnostic function.
For each output channel there are 2 bits in the diagnosis register coding the different failures; Refer to Chapter 8.3
for encoding details.
A short circuit to ground (SCG) will overwrite an open load (OL), but an open load (OL) will not overwrite a short
circuit to ground (SCG). In order to detect an open load (OL) after a short circuit to ground (SCG), the output has
to be programmed in Clear mode and again in either OFF mode or input mode with low input level.
Failure Mode
Comment
Open load or short circuit •
to ground
•
•
•
No diagnosis when channel n is switched on (either channel in ON mode or channel
in input mode and corresponding input signal is H)
No diagnosis when channel n is in Clear mode
Diagnosis when channel n is in input mode and corresponding input signal is L:
According to the voltage level at the output pin, the corresponding failure is latched
into the diagnosis register after the filtering time t_d has expired.
Diagnosis when channel n is in OFF mode: According to voltage level at the output
pin, the corresponding failure is latched into the diagnosis register after the filtering
time t_d has expired.
Data Sheet
18
Rev. 1.0, 2011-03-23