MUR480ES ONSEMI [ON Semiconductor], MUR480ES Datasheet - Page 4

• Manufacturer Part Number: MUR480ES
• Description: SWITCHMODE TM Power Rectifiers
• Manufacturer: ONSEMI [ON Semiconductor]

Figure 6 was used to demonstrate the controlled avalanche
capability of the new “E’’ series Ultrafast rectifiers. A
mercury switch was used instead of an electronic switch to
simulate a noisy environment when the switch was being
opened.
up linearly; and energy is stored in the coil. At t
is opened and the voltage across the diode under test begins
to rise rapidly, due to di/dt effects, when this induced voltage
reaches the breakdown voltage of the diode, it is clamped at
BV
which now starts to decay linearly through the diode, and
goes to zero at t
is opened; and calculating the energy that is transferred to
the diode it can be shown that the total energy transferred is
equal to the energy stored in the inductor plus a finite amount
of energy from the V
breakdown (from t
The unclamped inductive switching circuit shown in
When S
By solving the loop equation at the point in time when S
DUT
W
W
EQUATION (1):
EQUATION (2):
MERCURY
SWITCH
AVAL
AVAL
and the diode begins to conduct the full load current
1
is closed at t
[ 1
[ 1
S
1
2
.
2
2
Figure 6. Test Circuit
LI
LI
1
DD
2
LPK
to t
2
LPK
0
power supply while the diode is in
the current in the inductor I
2
) minus any losses due to finite
I
L
BV
DUT
BV
+V
40 mH COIL
DUT
DUT
DD
I
D
–V
DD
1
MUR480E, MUR4100E
the switch
CH1
CH2
V
L
CH1
http://onsemi.com
D
ramps
Figure 8. Current−Voltage Waveforms
500V
50mV
1
1
SAVEREF SOURCE
4
CH2
ACQUISITIONS
component resistances. Assuming the component resistive
elements are small Equation (1) approximates the total
energy transferred to the diode. It can be seen from this
equation that if the V
breakdown voltage of the device, the amount of energy
contributed by the supply during breakdown is small and the
total energy can be assumed to be nearly equal to the energy
stored in the coil during the time when S
Equation (2).
information obtained for the MUR8100E (similar die
construction as the MUR4100E Series) in this test circuit
conducting a peak current of one ampere at a breakdown
voltage of 1300 V, and using Equation (2) the energy
absorbed by the MUR8100E is approximately 20 mjoules.
condition, the new “E’’ series provides added protection
against those unforeseen transient viruses that can produce
unexplained random failures in unfriendly environments.
The oscilloscope picture in Figure 8, shows the
Although it is not recommended to design for this
t
0
A
Figure 7. Current−Voltage Waveforms
20ms
I
L
REF
953 V
217:33 HRS
DD
voltage is low compared to the
STACK
VERT
REF
t
1
BV
I
DUT
D
CHANNEL 2:
I
0.5 AMPS/DIV.
CHANNEL 1:
V
500 VOLTS/DIV.
TIME BASE:
20 ms/DIV.
L
DUT
t
1
2
was closed,
V
DD
t