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IRFB4620PBF Datasheet, PDF (5/8 Pages) International Rectifier – HEXFET Power MOSFET
IRFB4620PbF
10
1
D = 0.50
0.1
0.01
0.001
1E-006
0.20
0.10
0.05
0.02
0.01
SINGLE PULSE
( THERMAL RESPONSE )
1E-005
0.0001
τJ τJ
τ1 τ1
R1R1
Ci= τi/Ri
Ci i/Ri
R2R2
Ri (°C/W)
τCτ
0.456
τ2 τ2
0.589
τi (sec)
0.000311
0.003759
Notes:
1. Duty Factor D = t1/t2
2. Peak Tj = P dm x Zthjc + Tc
0.001
0.01
0.1
t1 , Rectangular Pulse Duration (sec)
Fig 13. Maximum Effective Transient Thermal Impedance, Junction-to-Case
100
Duty Cycle = Single Pulse
10
0.01
Allowed avalanche Current vs avalanche
pulsewidth, tav, assuming ∆Tj = 150°C and
Tstart =25°C (Single Pulse)
0.05
0.10
1
Allowed avalanche Current vs avalanche
pulsewidth, tav, assuming ∆Τ j = 25°C and
Tstart = 150°C.
0.1
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
120
TOP
Single Pulse
Notes on Repetitive Avalanche Curves , Figures 14, 15:
(For further info, see AN-1005 at www.irf.com)
BOTTOM 1.0% Duty Cycle
1. Avalanche failures assumption:
100
ID = 15A
Purely a thermal phenomenon and failure occurs at a temperature far in
excess of Tjmax. This is validated for every part type.
80
2. Safe operation in Avalanche is allowed as long asTjmax is not exceeded.
3. Equation below based on circuit and waveforms shown in Figures 16a, 16b.
4. PD (ave) = Average power dissipation per single avalanche pulse.
60
5. BV = Rated breakdown voltage (1.3 factor accounts for voltage increase
during avalanche).
6. Iav = Allowable avalanche current.
40
7. ∆T = Allowable rise in junction temperature, not to exceed Tjmax (assumed as
25°C in Figure 14, 15).
tav = Average time in avalanche.
20
D = Duty cycle in avalanche = tav ·f
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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