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IRFB7546PBF_15 Datasheet, PDF (6/10 Pages) International Rectifier – Brushed Motor drive applications
IRFB7546PbF
10
1
D = 0.50
0.20
0.10
0.1
0.05
0.02
0.01
0.01
SINGLE PULSE
( THERMAL RESPONSE )
0.001
1E-006
1E-005
0.0001
0.001
t1 , Rectangular Pulse Duration (sec)
Notes:
1. Duty Factor D = t1/t2
2. Peak Tj = P dm x Zthjc + Tc
0.01
0.1
Fig 14. Maximum Effective Transient Thermal Impedance, Junction-to-Case
100
Allowed avalanche Current vs avalanche
pulsewidth, tav, assuming Tj = 150°C and
Tstart =25°C (Single Pulse)
10
1
Allowed avalanche Current vs avalanche
pulsewidth, tav, assuming  j = 25°C and
Tstart = 150°C.
0.1
1.0E-06
1.0E-05
1.0E-04
tav (sec)
1.0E-03
1.0E-02
1.0E-01
Fig 15. Avalanche Current vs. Pulse Width
120
TOP
Single Pulse
BOTTOM 1.0% Duty Cycle
100
ID = 45A
80
60
40
20
0
25
50 75 100 125 150 175
Starting TJ , Junction Temperature (°C)
Fig 16. Maximum Avalanche Energy vs. Temperature
Notes on Repetitive Avalanche Curves , Figures 15, 16:
(For further info, see AN-1005 at www.irf.com)
1.Avalanche failures assumption:
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
23a, 23b.
4. PD (ave) = Average power dissipation per single avalanche pulse.
5. BV = Rated breakdown voltage (1.3 factor accounts for voltage
increase during avalanche).
6. Iav = Allowable avalanche current.
7. T = Allowable rise in junction temperature, not to exceed Tjmax
(assumed as 25°C in Figure 14, 15).
tav = Average time in avalanche.
D = Duty cycle in avalanche = tav ·f
ZthJC(D, tav) = Transient thermal resistance, see Figures 14)
PD (ave) = 1/2 ( 1.3·BV·Iav) = T/ ZthJC
Iav = 2T/ [1.3·BV·Zth]
EAS (AR) = PD (ave)·tav
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November 7, 2014