ICLS6022J Datasheet, PDF (22/33 Pages) Infineon Technologies AG – LED System Driver ICs

LED System Driver ICs
ICLS6x Series
Functional Description
3.6.2 Protection Modes
The IC provides several protection features to increase the LED drive’s robustness and safety. The following table
shows the possible system failures and the corresponding protection modes.
Table 3 Protection modes
VCC Overvoltage
Overtemperature
Overload
Open Loop
VCC Undervoltage
Floating Load Protection (FLP)
Auto Restart mode during startup
Auto Restart mode during RUN mode
Auto Restart mode during RUN mode
Auto Restart mode during RUN mode
Auto Restart mode during RUN mode
Floating Load Protection mode
3.6.2.1 Auto Restart Mode during Startup
The VCC voltage is observed by the comparator C13 if 20.5 V is exceeded. The output of C13 is combined with
both the output of C3, which checks for V_SoftS < 4.0 V, and the output of C4, which checks for V_FB > 4.5 V.
Therefore, overvoltage detection can only be active during the soft start phase (V_SoftS < 4.0 V) and if the FB signal
is outside the operating range (> 4.5 V). This means any small voltage overshoots of V_VCC occurring during normal
operation cannot trigger the Auto Restart mode during startup.
SoftS
C3
4.0V
UVLO
S
RQ
FF2
VCC
C13
20.5V
C4
4.5V
Auto
Restart
Mode
&
G13
Spike
Blanking
8.0us
&
G 12
Thermal Shutdown
Tj >140°C
Internal
Bias
Control Unit
FB
Figure 16 Auto Restart mode during startup
In order to ensure system reliability and prevent any false activation, a blanking time is implemented before the IC
can enter Auto Restart mode during startup. The output of the VCC overvoltage detection circuit is fed into a spike
blanking with a time constant of 8.0 µs.
Data Sheet
22
Version 1.0, 2011-05-19