ICLS602X datasheet(18/33 Pages) INFINEON

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LED System Driver ICs

ICLS6x Series

Functional Description

Data Sheet

Version 1.0, 2011-05-19

3.5

Current Limiting

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 RSense. By means of RSense the source current is transformed to a sense voltage VSense which is fed to the

CS pin. If VSense exceeds the internal threshold voltage Vcsth 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.

Current Limiting

C10

Propagation Delay

Compensation

csth

PWM Latch

FF1

10k

1pF

PWM-OP

Leading

Edge

Blanking

220 ns

ICLS602X Datasheet(PDF) 18 Page - Infineon Technologies AG