Datasheet
DTO25
www.vishay.com
Vishay Sfernice
Revision: 23-Oct-2019
4
Document Number: 51054
For technical questions, contact: sferfixedresistors@vishay.com
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ENERGY CURVE at 25 °C
POWER CURVE at 25 °C
Single Pulse:
These informations are for a single pulse on a cold resistor
at 25 °C (not already used for a dissipation) and for pulses
of 100 ms maximum duration.
The formula used to calculate E is:
with:
E (J): Pulse energy
P (W): Pulse power
t (s): Pulse duration
U (V): Pulse voltage
R (): Resistor
The energy calculated must be less than that allowed by the
graph.
Repetitive or Superimposed Pulses:
The following formula is used to calculate the “equivalent“
energy of a repetitive pulse or the “equivalent energy“ of a
pulse on a resistor that is already dissipating power.
with:
E
c
(J): Equivalent pulse energy
E (J): Known pulse energy
P
r
: Resistor power rating
P
a
: Mean power being dissipated
The energy calculated must be less than that allowed by the
graph and the average power dissipated (P
a
) must not
exceed the continuous power of resistor.
10
100
1000
10000
0.001
0.01
0.1
1
10
100
0.0000001 0.000001 0.00001 0.0001 0.001 0.01 0.1
Axis Title
1st line
2nd line
2nd line
Energy (J)
Overloard Duration (s)
10
100
1000
10000
10
100
1000
10 000
100 000
0.0000001 0.000001 0.00001 0.0001 0.001 0.01 0.1
Axis Title
1st line
2nd line
x
Power (W)
Overload Duration (s)
E P x t
U
2
R
--------
x t==
E
c
E x 1
P
a
P
r
------
+
=