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AUIRFS8409-7P Datasheet, PDF (5/12 Pages) International Rectifier – HEXFETPower MOSFET
AUIRFS8409-7P
1
D = 0.50
0.1
0.20
0.10
0.05
0.01
0.02
0.01
0.001
0.0001
1E-006
1000
100
10
SINGLE PULSE
( THERMAL RESPONSE )
Notes:
1. Duty Factor D = t1/t2
2. Peak Tj = P dm x Zthjc + Tc
1E-005
0.0001
0.001
0.01
0.1
t1 , Rectangular Pulse Duration (sec)
Fig 13. Maximum Effective Transient Thermal Impedance, Junction-to-Case
Duty Cycle = Single Pulse
0.01
0.05
0.10
Allowed avalanche Current vs avalanche
pulsewidth, tav, assuming ΔTj = 150°C and
Tstart =25°C (Single Pulse)
Allowed avalanche Current vs avalanche
pulsewidth, tav, assuming ΔΤ j = 25°C and
Tstart = 150°C.
1
1.0E-06
1.0E-05
1.0E-04
1.0E-03
1.0E-02
tav (sec)
Fig 14. Typical Avalanche Current vs.Pulsewidth
1.0E-01
800
Notes on Repetitive Avalanche Curves , Figures 14, 15
TOP
Single Pulse
(For further info, see AN-1005 at www.irf.com)
700
BOTTOM 1.0% Duty Cycle
1. Avalanche failures assumption:
ID = 100A
600
Purely a thermal phenomenon and failure occurs at a temperature far in
excess of Tjmax. This is validated for every part type.
2. Safe operation in Avalanche is allowed as long asTjmax is not exceeded.
3. Equation below based on circuit and waveforms shown in Figures 24a, 24b.
500
4. PD (ave) = Average power dissipation per single avalanche pulse.
5. BV = Rated breakdown voltage (1.3 factor accounts for voltage increase
400
during avalanche).
6. Iav = Allowable avalanche current.
300
7. ΔT = Allowable rise in junction temperature, not to exceed Tjmax (assumed as
25°C in Figure 14, 15).
200
tav = Average time in avalanche.
D = Duty cycle in avalanche = tav ·f
100
ZthJC(D, tav) = Transient thermal resistance, see Figures 13)
0
25 50 75 100 125 150 175
Starting TJ , Junction Temperature (°C)
Fig 15. Maximum Avalanche Energy vs. Temperature
PD (ave) = 1/2 ( 1.3·BV·Iav) = DT/ ZthJC
Iav = 2DT/ [1.3·BV·Zth]
EAS (AR) = PD (ave)·tav
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April 30, 2013