VIPER06HS STMicroelectronics, VIPER06HS Datasheet - Page 20

• Manufacturer Part Number: VIPER06HS
• Description: AC/DC Switching Converters Fixed VIPer Plus 800V 115kHz 30mW
• Manufacturer: STMicroelectronics

Specifications of VIPER06HS

• Product Category: AC/DC Switching Converters
• Rohs: yes

Open-loop failure protection
15
20/28
Open-loop failure protection
If the power supply has been designed using flyback topology and the VIPER06 is supplied
by an auxiliary winding, as shown in
protected against feedback loop failure or accidental disconnections of the winding.
The following description is applicable for the schematics of
page
If R
voltage, V
output through the secondary-to-auxiliary turns ratio.
As the auxiliary voltage increases up to the internal V
given in
threshold, I
generated.
In order to distinguish an actual malfunction from a bad auxiliary winding design, both the
above conditions (drain current equal to the drain current limitation and current higher than
I
If R
voltage V
isolated flyback).
Figure 27. FB pin connection for non-isolated flyback
DDol
H
L
is open or R
through the VDD clamp) have to be verified to reveal the fault.
is open or R
21, respectively the non-isolated flyback and the isolated flyback.
Table 7 on page
REF_FB
OUT
DDol
, will increase as does the auxiliary voltage, V
R
R
(the value is given in
H
L
(for non-isolated flyback) or to the external TL voltage reference (for
V
H
L
OUT
is shorted, the VIPER06 works at its drain current limitation. The output
is shorted, the output voltage, V
8) and the clamp current injected on the VDD pin exceeds the latch
FB
C
VDD
V
Doc ID 022794 Rev 1
REF_FB
VDD
-
+
E/A
Figure 27
Table 7 on page
C
COMP
P
BUS
and
R
C
S
S
nR
V
from R
COMPL
OUT
Figure 28 on page
DD
R
8), a fault signal is internally
SENSE
, will be clamped to the reference
+
-
+
-
active clamp, V
AUX
Figure 27
PWM stop
to PWM
, which is coupled with the
R
AUX
21, the converter is
and
DDclamp
D
AUX
Figure 28 on
(the value is
VIPER06
V
AUX