NCP1340 Datasheet, PDF (27/32 Pages) ON Semiconductor – High-Voltage, Quasi-Resonant, Controller Featuring Valley Lock-Out Switching

NCP1340
Overload Protection
The overload timer integrates the duration of the overload
fault. That is, the timer count increases while the fault is
present and reduces its count once it is removed. The
overload timer duration, t_OVLD, is typically 160 ms. When
the overload timer expires, the controller detects an overload
condition does one of the following:
• The controller latches off (version A) or
• Enters a safe, low duty−ratio auto−recovery mode
(version B).
Figure 23 shows the overload circuit schematic, while
Figure 24 and Figure 25 show operating waveforms for
latched and auto−recovery overload conditions.
Figure 23. Overload Circuitry
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