VIPER15

Manufacturer Part NumberVIPER15
DescriptionVIPerPlus family: quasi-resonant high performance off line high voltage converter
ManufacturerSTMicroelectronics
VIPER15 datasheet

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VIPER15
Figure 38. Brown-out protection: BR external setting and timing diagram
VDD
V
IN_DC
R
H
BR
C
R
L
I
BRhyst
Fixed the V
and the V
INon
can be established for the calculation of the resistors R
Equation 12
Equation 13
For a proper operation of this function, V
minimum mains and V
minimum mains and maximum load.
The BR pin is a high impedance input connected to high value resistors, thus it is prone to
pick up noise, which might alter the OFF threshold when the converter operates or gives
origin to undesired switch-off of the device during ESD tests.
It is possible to bypass the pin to ground with a small film capacitor (e.g. 1-10 nF) to prevent
any malfunctioning of this kind.
If the brown-out function is not used the BR pin has to be connected to GND, ensuring that
the voltage is lower than the minimum of V
enable the brown-out function the BR pin voltage has to be higher than the maximum of
V
threshold (150 mV, see
DIS
V
IN
V
INon
V
INoff
V
DRAIN_START
+
V
BR
V
BRth
V
V
in_OK
+
DIS
I
-
Disable
BR
I
BRhyst
V
+
DD
V
DDon
V
V
-
V
BRth
in_OK
DDoff
V
DD(RESTART)
V
DS
V
OUT
levels, with reference to
INoff
V
V
V
BRhyst
INon
INoff
=
+
R
L
I
V
BRhyst
INoff
V
V
V
INon
INoff
BRhyst
=
R
H
I
BRhyst
must be less than the peak voltage at
IN on
less than the minimum voltage on the input bulk capacitor at
IN off
threshold (50 mV, see
DIS
Table 8
).
Doc ID 15455 Rev 5
Operation description
Figure 38
, the following relationships
and R
:
H
L
V
V
BRhyst
×
BRth
V
I
BRth
BRhyst
R
×
L
V
BRhyst
+
R
L
I
BRhyst
Table 8
). In order to
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