™
PROFET + 24V
BTT6200-4ESA
Diagnostic functions
IIS
IIS(OL)
IL
IL(OL)
Sense for OL.vsd
Figure 24
Current sense ratio for low currents
7.3.3.2
Open load in OFF diagnostic
For open load diagnosis in OFF-state, an external output pull-up resistor (ROL) is recommended. For the
calculation of pull-up resistor value, the leakage currents and the open load threshold voltage VOL(OFF) have to
be taken into account. Figure 25 gives a sketch of the situation. Ileakage defines the leakage current in the
complete system, including IL(OFF) (see Chapter 5.5) and external leakages, e.g, due to humidity, corrosion, etc...
in the application.
To reduce the stand-by current of the system, an open load resistor switch SOL is recommended. If the channel x
is OFF, the output is no longer pulled down by the load and VOUT voltage rises to nearly VS. This is recognized by
the device as an open load. The voltage threshold is given by VOL(OFF). In that case, the SENSE signal is switched
to the IIS(FAULT)
.
An additional RPD resistor can be used to pull VOUT to 0 V. Otherwise, the OUT pin is floating. This resistor can be
used as well for short circuit to battery detection, see Chapter 7.3.4
Datasheet
31
Rev. 1.00
2019-03-09
INFINEON [ Infineon ]
