TLE8110EE_13 Datasheet, PDF (35/74 Pages) Infineon Technologies AG – Overvoltage, Overtemperature, ESD -Protection

TLE 8110 EE
Smart Multichannel Switch
Protection Functions
10
Protection Functions
The device provides embedded protective functions. Integrated protection functions are designed to prevent IC
destruction under fault conditions described in this Document. Fault conditions are considered “outside” the
normal operating range. Protection functions are not designed for continuous repetitive operation.
There is an over load and over temperature protection implemented in the TLE8110EE.
If a protection function becomes active during the write cycle of Diagnosis Information into the Diagnosis Register,
the information is latched and stored into the diagnosis register after the write process.
In order to achieve a maximum protection, the affected channel with over current or over temperature (OCT) is
switched and latched OFF, channel can be turned ON again after the diagnosis register is cleared
(Chapter 12.3.2) or if a different new diagnosis overrides the OCT.
For the failure condition of Reverse Currents, the device contains a “Reverse Current Protection Comparator”
[RCP]. This RCP can optionally be activated by setting the DEVS.RCP Bit.
In case the comparator is activated, it detects a reverse current and switches ON the related output channel. The
channel is kept ON up to a reverse current channel dependent threshold I_{RCP_off}. This threshold is defined by
regulators target value to keep the output voltage at >/~-0.3V. If the current exceeds a defined value, the
comparator switches OFF and other protection functions are protecting the circuit against reverse current. That
means that at higher currents / or in case RCP is de-activated / not activated, the reverse current is flowing through
the body diode of the DMOS. In that case, the voltage drops to typically -0.6V according the voltage of the body
diode. In case the comparator threshold has been exceeded and the RCP has been switched OFF, the functions
remains OFF until the reverse current arrives back to zero reverse current. Only then, the comparator can be
activated again after a delay time t_{RCP_on_delay}.
This function reduces the un-wanted influence of a reverse current to the analogue part of the circuit (such as the
diagnosis). For more details about the functionality, see Figure 23 and Figure 24 and concerning the settings and
the related registers, refer to Chapter “Control of the Device”.
Serial
control
Logic
Ctrl.
RCP
Ref.
-300mV
temperature
sensor
T
gate
control
short circuit
detection
OUTx
Figure 21 Block Diagram Protection Functions
Block _diag_Protection.vsd
Data Sheet
35
Rev. 1.4, 2013-07-02