viper22as13tr STMicroelectronics, viper22as13tr Datasheet - Page 10
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viper22as13tr
Manufacturer Part Number
viper22as13tr
Description
Low Power Off Line Smps Primary Switcher
Manufacturer
STMicroelectronics
Datasheet
1.VIPER22AS13TR.pdf
(15 pages)
Available stocks
Company
Part Number
Manufacturer
Quantity
Price
Part Number:
VIPER22AS13TR
Manufacturer:
ST
Quantity:
20 000
VIPer22ADIP / VIPer22AS
Figure 11 : Start Up Sequence
the regulation point where the secondary loop
begins to send a current in the optocoupler. At this
point, the converter enters a regulated operation
where the FB pin receives the amount of current
needed to deliver the right power on secondary
side.
This sequence is shown in figure 11. Note that
during the real starting phase t
consumes some energy from the V
waiting for the auxiliary winding to provide a
continuous supply. If the value of this capacitor is
too low, the start up phase is terminated before
receiving any energy from the auxiliary winding
and the converter never starts up. This is illustrated
also in the same figure in dashed lines.
10/15
V
V
V
V
OUT
DDon
DDoff
DD
I
FB
tss
ss
, the device
DD
capacitor,
t
t
t
Figure 12 : Overvoltage Sequence
OVERVOLTAGE THRESHOLD
An overvoltage detector on the V
VIPer22A to reset itself when V
V
the whole sequence of an overvoltage event. Note
that this event is only latched for the time needed
by V
resumes normal operation automatically.
DDovp
V
V
V
V
DDovp
V
DDoff
DDon
DD
DD
DS
. This is illustrated in figure 12, which shows
to reach V
DDoff
, and then the device
DD
pin allows the
DD
exceeds
t
t