VIPER20-E STMicroelectronics, VIPER20-E Datasheet - Page 14

• Manufacturer Part Number: VIPER20-E
• Description: IC SWIT SMPS CM OTP PENTAWATT5
• Manufacturer: STMicroelectronics
• Series: VIPER™r

Specifications of VIPER20-E

• Output Isolation: Isolated
• Frequency Range: 90 ~ 200kHz
• Voltage - Input: 8 ~ 15 V
• Voltage - Output: 620V
• Power (watts): 57W
• Operating Temperature: 25°C ~ 125°C
• Package / Case: Pentawatt-5 HV (Bent and Staggered Leads)
• Mounting Style: Through Hole
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Other names: 497-6794-5; VIPER20-E

5 Operation Description
5.5
5.6
5.7
14/31
External Clock Synchronization:
The OSC pin provides a synchronisation capability when connected to an external frequency
source.
If the proposed schematic is used, the pulse duration must be kept at a low value (500ns is
sufficient) for minimizing consumption. The optocoupler must be able to provide 20mA through
the optotransistor.
Primary Peak Current Limitation
The primary I
simple circuit shown in
the COMP pin in order to limit the primary peak current of the device to a value:
where:
The suggested value for R
Over-Temperature Protection
Over-temperature protection is based on chip temperature sensing. The minimum junction
temperature at which over-temperature cut-out occurs is 140ºC, while the typical value is
170ºC. The device is automatically restarted when the junction temperature decreases to the
restart temperature threshold that is typically 40ºC below the shutdown value
I
V
D PEAK
COMP
Figure 21
=
=
DPEAK
0.6
V
------------------------------- -
COMP
×
shows one possible schematic to be adapted, depending the specific needs.
R
------------------ -
H
1
ID
current and, consequently, the output power can be limited using the
R
+
–
2
R
0.5
Figure 22
2
1
+R
2
is in the range of 220K Ω .
. The circuit based on Q1, R
1
and R
2
clamps the voltage on
VIPer20-E/DIP-E
(see Figure 13)