TLD1314EL_15 Datasheet, PDF (18/29 Pages) Marl International Limited – Basic LED Driver

TLD1314EL
Load Diagnosis
8
Load Diagnosis
The diagnosis function is enabled, if the voltage at the DEN pin V_DEN is above V_DEN(act) as described in Chapter 5.
8.1
Open Load
An open load diagnosis feature is integrated in the TLD1314EL driver IC. If there is an open load on one of the
outputs, the outputs are turned off. The potential on the IN_SET pin rises up to V_{IN_SET(OL/SC)}, if the ST is connected
to GND. This high voltage can be used as input signal for an µC as shown in Figure 8. If the ST pin is open or
connected to GND via a high ohmic resistor, the ST pin rises to a high potential as described in Chapter 7. More
details are shown in Figure 17. 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)}
V_{IN_ SET( ref )}
t_OL
t_{IN _SET (re set)}
t
V_OUT
V_S
VS – VPS(OL )
V_F
open load
occurs
open load
disappears
t
Figure 14 IN_SET behavior during open load condition with ST pin connected to GND and V_DEN > V_DEN(act)
Data Sheet
18
Rev. 1.1, 2015-03-24