TLE8108EM Datasheet, PDF (16/30 Pages) Infineon Technologies AG – Smart 8-Channel Low Side Relay Driver with SPI Interface

TLE 8108 EM
Smart 8-Channel Low Side Switch
Protection Functions
6
Protection Functions
The device provides embedded protective functions. Integrated protection functions are designed to prevent IC
destruction under fault conditions described in this Data Sheet. Fault conditions are considered as “outside”
normal operating range. Protection functions are not designed for continuous repetitive operation.
6.1
Overload Protection
The TLE8108EM is protected in case of Overload or short circuit of the load. After time t_OFF(OVL), the overloaded
channel n switches off and the according diagnosis information is stored into the corresponding diagnosis register.
The channel can be switched on again with the corresponding command after programming the Clear mode to
reset the diagnosis register. Please refer to the example from Figure 8 for details.
Channel
Command
ON
OFF
ON
CLR
t_OFF(OVL2)
I_D
I_D(OVL2)
I_D(OVL1)
Overload
Removed
t_OFF(OVL1)
Figure 8 Shutdown at Overload
Reset of
SCB entry
ON
t
t
Overload Timing.vsd
6.2
Overtemperature Protection
In case of Overload, a temperature sensor for each channel causes an overheated channel n to switch off to
prevent destruction and the according diagnosis information is stored into the corresponding diagnosis register.
The channel can be switched on again after programming the Clear mode and sending the ON command
afterwards. Please refer to Chapter 7 for information on diagnosis features.
6.3
Reverse Polarity Protection
In case of reverse polarity, the intrinsic body diode of the n-MOSFET generates power to be dissipated. The
reverse current through the intrinsic body diode of the power transistor has to be limited by the connected load.
The VDD supply pins must be protected against reverse polarity externally.
Data Sheet
16
Rev. 1.0, 2011-03-23