Datasheet

Functional check AN4260
14/29 DocID024275 Rev 2
6 Functional check
6.1 Startup
The startup phase at maximum load is shown in Figure 19 and Figure 21 at both nominal
input voltages (115 V
AC
and 230 V
AC
).
6.2 Overload protection
In case of overload or short-circuit (see Figure 23), the drain current reaches the I
DLIM
value
(or the one set by the user through the RLIM resistor). In every cycle where this condition is
met, a counter is incremented; if it is maintained continuously for the time t
OVL
(50 msec
typical, internally set) the overload protection is tripped, the power section is turned off and
the converter is disabled for a t
RESTART
time (1 sec typical). After this time has elapsed, the
IC resumes switching and, if the short is still present, the protection occurs indefinitely in the
same way (Figure 24). This ensures restart attempts of the converter with low repetition
rate, so that it works safely with extremely low power throughput and avoids the IC
overheating in case of repeated overload events.
Figure 19. Startup at V
IN
= 115 V
AC
, full load Figure 20. Startup at V
IN
= 115 V
AC
, full load,
zoom
Figure 21. Startup at V
IN
= 230 V
AC
, full load Figure 22. Startup at V
IN
= 230 V
AC
, full load,
zoom
I_L2
AM16645v1
AM16646v1
I_L2
AM16647v1
AM16648v1