ICLS6022J Datasheet, PDF (18/33 Pages) Infineon Technologies AG – LED System Driver ICs

3.5
Current Limiting
PWM Latch
FF1
LED System Driver ICs
ICLS6x Series
Functional Description
Current Limiting
Propagation Delay
Compensation
C10
PWM-OP
V_{c s th}
Leading
Edge
Blanking
220 ns
10kΩ
1pF
D1
CS
Figure 10 Current limiting
Cycle-by-cycle current limiting realized by the current limit comparator C10 to provide overcurrent detection (see
Figure 10). The source current of the integrated depletion CoolMOS™ is sensed by means of an external sense
resistor R_Sense. By means of R_Sense the source current is transformed to a sense voltage V_Sense which is fed to the
CS pin. If V_Sense exceeds the internal threshold voltage V_csth the comparator C10 immediately turns off the gate
drive by resetting the PWM latch FF1. A Propagation Delay Compensation circuit is added to support immediate
shutdown without delay of the integrated internal CoolMOS™ in the case of current limiting. The influence of the
AC input voltage on the maximum output power can be suppressed as a result.
To prevent the current limiting function from causing distortions by leading edge spikes, a Leading Edge Blanking
circuit is integrated into the current sense path for the comparator C10 and the PWM OP.
Data Sheet
18
Version 1.0, 2011-05-19