TLD1125EL_15 Datasheet, PDF (25/36 Pages) Marl International Limited – Basic LED Driver

V_{IN_ SET}
V_{IN_ SET(ref )}
V_ST
V_{ST (OL )}
TLD1125EL
Load Diagnosis
t
V_D
t
V_{D( th)}
tD
tIN_ SET (re se t)
t
V_OUT
VS
V_S – V_{PS( OL)}
VF
open load
occurs
open load
disappears
t
Figure 21 IN_SET and ST behavior during open load condition (ST unconnected)
To provide a Limp Home functionality (reactivation in case of open load instead of complete deactivation) the filter
time t_D can be used. If a PWM signal with a frequency higher than 1/t_D is applied to the V_S line and EN signal, the
OL detection feature will not be activated. The implementation of the D-pin is shown in the following figure:
I_D
D
Output Control
VD
Figure 22 Block Diagram D pin
Data Sheet
25
Rev. 1.0, 2013-08-08