NCP1238
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34
Figure 63. Latch−off Function Timing Diagram
time
Internal Latch Signal
time
V
CC
time
DRV
V
CC(on)
V
CC(min)
Latch signal
high during
pre-start phase
Noise spike
ignored
(t
Latch
blanking)
Start-up
initiated by
V
CC(on)
Switching
allowed (no
latch event)
Latch-off
Temperature shutdown
The die includes a temperature shutdown protection with
a turn−off threshold guaranteed between 140°C and 160°C,
and a typical hysteresis of 30°C. When the temperature rises
above the high threshold, the controller stops switching
instantaneously, the HV current source is turned off, and the
internal logic state is reset.
When the temperature falls below the low threshold, the
HV startup current source is enabled, and a regular startup
sequence takes place.
