AUIRFZ44VZS Datasheet, PDF (7/11 Pages) International Rectifier – AUTOMOTIVE GRADE

AUIRFZ44VZS
1000
Duty Cycle = Single Pulse
100
0.01
10
0.05
0.10
1
Allowed avalanche Current vs
avalanche pulsewidth, tav
assuming  Tj = 25°C due to
avalanche losses. Note: In no
case should Tj be allowed to
exceed Tjmax
0.1
1.0E-06
1.0E-05
1.0E-04
tav (sec)
1.0E-03
1.0E-02
Fig 15. Typical Avalanche Current Vs. Pulse width
1.0E-01
80
TOP
Single Pulse
BOTTOM 1% Duty Cycle
ID = 34A
60
40
20
0
25
50
75
100 125 150 175
Starting TJ , Junction Temperature (°C)
Notes on Repetitive Avalanche Curves , Figures 15, 16:
(For further info, see AN-1005 at www.infineon.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 as Tjmax is not exceeded.
3. Equation below based on circuit and waveforms shown in Figures 12a, 12b.
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 13)
P_{D (ave)} = 1/2 ( 1.3·BV·I_av) = T/ Z_thJC
I_av = 2T/ [1.3·BV·Z_th]
E_{AS (AR)} = P_{D (ave)}·t_av
Fig 16. Maximum Avalanche Energy vs. Temperature
7
2015-10-27