AUIRFI4905 Datasheet, PDF (5/9 Pages) International Rectifier – Advanced Planar Technology

5000
4000
3000
ID
TOP -8.8A
-13A
BOTTOM -23A
2000
1000
0
25
50
75
100 125 150
Starting TJ , Junction Temperature (°C)
Fig 12. Maximum Avalanche Energy vs. Drain Current
100
10
AUIRFI4905
4.5
4.0
3.5
3.0
2.5
ID = -250µA
ID = -1.0mA
ID = -1.0A
2.0
1.5
-75 -50 -25 0 25 50 75 100 125 150 175
TJ , Temperature ( °C )
Fig 13. Threshold Voltage vs. Temperature
Allowed avalanche Current vs avalanche
pulsewidth, tav, assuming Tj = 150°C and
Tstart =25°C (Single Pulse)
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
1.0E-03
1.0E-02
tav (sec)
1.0E-01
1.0E+00
1.0E+01
Fig 14. Typical Avalanche Current vs. Pulse Width
1400
1200
1000
TOP
Single Pulse
BOTTOM 1.0% Duty Cycle
ID = -23A
800
600
400
200
0
25 50 75 100 125 150 175
Notes on Repetitive Avalanche Curves , Figures 14, 15:
(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 as Tjmax 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.
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)
Starting TJ , Junction Temperature (°C)
Fig 15. Maximum Avalanche Energy vs. Temperature
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
5 www.irf.com © 2013 International Rectifier
September 11, 2013