BTS7012-2EPA
PROFET™ +2 12V
Diagnosis
9.3.1
Open Load current (IIS(OLOFF))
In OFF state, when DEN pin is set to “high” and a channel is selected using DSEL pin, the VDS voltage is
compared with a threshold voltage VDS(OLOFF). If the load is properly connected and there is no short circuit to
battery, VDS ~ VS therefore VDS > VDS(OLOFF). When the diagnosis is active and VDS ≤ VDS(OLOFF), a current IIS(OLOFF) is
provided by IS pin. Figure 38 shows the relationship between IIS(OLOFF) and IIS(FAULT) as functions of VDS. The two
currents do not overlap making it always possible to differentiate between Open Load in OFF and Fault
condition.
IIS
IIS(FAULT)
IIS(OLOFF)
VDS(OLOFF)
VDS
Figure 38
IIS in OFF State
It is necessary to wait a time tIS(OLOFF)_D between the falling edge of the input pin and the sensing at pin IS for
Open Load in OFF diagnosis to allow the internal comparator to settle. In Figure 39 the timings for an Open
Load detection are shown - the load is always disconnected.
IN
t
DEN
tIS(OLOFF)_D
t
VOUT
VDS(OLOFF)
~ VS
Load
conn ect ed
t
t
IIS
IIS(OLOFF)
IIS(OL)
Diagnosis_PROFET_OLOFF_time.emf
Figure 39 Open Load in OFF Timings - load disconnected
Data Sheet
47
Rev. 1.10
2020-12-14
INFINEON [ Infineon ]
