TLD1121EL Datasheet, PDF (20/31 Pages) Infineon Technologies AG – 1 Channel High Side Current Source Basic LED Driver

TLD1121EL
Load Diagnosis
8
Load Diagnosis
8.1
Open Load
An open load diagnosis feature is integrated in the TLD1121EL driver IC. If there is an open load on the output,
the output is turned off. The potential on the IN_SET pin rises up to V_{IN_SET(OL/SC)}. This high voltage can be used
as input signal for an µC as shown in Figure 9. The open load status is not latched, as soon as the open load
condition is no longer present, the output stage will be turned on again. An open load condition is detected, if the
voltage drop over the output stage V_PS is below the threshold according Pos. 8.3.10 and a filter time of t_OL is
passed.
V _{I N_ SET}
V_{IN _SET( OL /SC)}
VIN_ SET( ref )
t_OL
t_{IN _SET (re set)}
t
V_OUT
VS
V_S – V_{PS(OL )}
VF
open load
occurs
open load
disappears
t
Figure 15 IN_SET behavior during open load condition with ST pin connected to GND
Data Sheet
20
Rev. 1.0, 2013-08-08