VIPER37HE STMicroelectronics, VIPER37HE Datasheet - Page 30

• Manufacturer Part Number: VIPER37HE
• Description: AC/DC Switching Converters ViperPlus Fixed Freq 800V 30mQ 265 Vac
• Manufacturer: STMicroelectronics
• Type: Off Line Switcherr

Specifications of VIPER37HE

• Product Category: AC/DC Switching Converters
• Rohs: yes
• Input / Supply Voltage (max): 23.5 V
• Input / Supply Voltage (min): 8.5 V
• Switching Frequency: 115 kHz
• Supply Current: 3.5 mA
• Operating Temperature Range: - 40 C to + 150 C
• Mounting Style: Through Hole
• Package / Case: SDIP-10
• Maximum Operating Temperature: + 125 C
• Minimum Operating Temperature: - 25 C
• Number Of Outputs: 1
• Output Power: 25 W

Operation description
30/35
Figure 33. Brownout protection: BR external setting and timing diagram
When the V
relationships can be established for the calculation of the resistors R
Equation 9
Equation 10
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, it is therefore prone
to pick up noise, which might alter the OFF threshold when the converter operates or
creates an 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 brownout function is not used, the BR pin must be connected to GND, ensuring that
the voltage is lower than the minimum V
INon
and the V
R
R
L
IN off
=
H
=
−
INoff
V
less than the minimum voltage on the input bulk capacitor at
V
I
BRhyst
BRhyst
INon
Doc ID 022218 Rev 1
levels are fixed, with reference to
−
V
+
I
BRhyst
INoff
V
INon
DIS
IN on
−
V
V
−
INoff
threshold (50 mV), see
BRhyst
V
must be less than the peak voltage at
INoff
−
V
×
−
BRth
R
V
BRhyst
L
+
R
V
I
BRhyst
BRhyst
L
×
I
V
BRhyst
Figure 33
BRth
Table 8
H
and R
, the following
.
L
:
VIPER37