VIPER20 STMicroelectronics, VIPER20 Datasheet - Page 17

• Manufacturer Part Number: VIPER20
• Manufacturer: STMicroelectronics

Specifications of VIPER20

• Pwm Type: Current Mode PWM Controller
• Number Of Pwm Outputs: 1
• On/off Pin: No
• Adjustable Output: No
• Switching Freq: 200kHz
• Operating Supply Voltage (max): 15V
• Output Current: 500mA
• Output Voltage: 620V
• Synchronous Pin: No
• Rise Time: 50ns
• Fall Time: 100ns
• Mounting: Through Hole
• Pin Count: 5 +Tab
• Package Type: PENTAWATT HV
• Lead Free Status / Rohs Status: Not Compliant

Figure 23: Recommended Layout
LAYOUT CONSIDERATIONS
Some simple rules insure a correct running of
switching power supplies. They may be classified
into two categories:
- To minimize power loops: the way the switched
power current must be carefully analyzed and
the corresponding paths must present the
smallest possible inner loop area. This avoids
radiated EMC noises, conducted EMC noises
by magnetic coupling, and provides a better
efficiency by eliminating parasitic inductances,
especially on secondary side.
GL RG H V EU L GJH
) U RP L QSX W
C1
R1
C2
1
U1
VIPerXX0
OSC
13V
ISO1
2
VDD
+
-
C3
COMP
R2
C4
5
SOURCE
DRAIN
In case of VIPer, these rules apply as shown in
figure 23. The loops C1-T1-U1, C5-D2-T1, C7-D1-
T1 must be minimized. C6 must be as close as
possible to T1. The signal components C2, ISO1,
C3 and C4 use a dedicated track to be connected
directly to the source of the device.
4
3
- To use different tracks for low level signals and
power ones. The interferences due to a mixing
of signal and power may result in instabilities
and/or anomalous behavior of the device in
case of violent power surge (Input overvoltages,
output short circuits...).
VIPer20/SP/DIP - VIPer20A/ASP/ADIP
C5
D2
T1
C6
D1
FC00500
C7
IL O W H U L QJ D Q G O RD G
7R V HFRQ G D U \
17/25
1