IRFB4020PBF Datasheet, PDF (5/7 Pages) International Rectifier – DIGITAL AUDIO MOSFET

300
275
ID = 11A
250
225
200
TJ = 125°C
175
150
125
100
TJ = 25°C
75
50
5 6 7 8 9 10 11 12 13 14 15 16
VGS, Gate -to -Source Voltage (V)
Fig 12. On-Resistance vs. Gate Voltage
1000
100
Duty Cycle = Single Pulse
10
0.01
0.05
1
0.10
IRFB4020PbF
400
ID
TOP 1.6A
2.4A
300
BOTTOM 11A
200
100
0
25 50 75 100 125 150 175
Starting TJ , Junction Temperature (°C)
Fig 13. Maximum Avalanche Energy vs. Drain Current
Allowed avalanche Current vs
avalanche pulsewidth, tav
assuming ∆ Tj = 25°C due to
avalanche losses
0.1
0.01
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
100
TOP
Single Pulse
BOTTOM 1.0% Duty Cycle
80
ID = 11A
60
40
20
0
25 50 75 100 125 150 175
Starting TJ , Junction Temperature (°C)
Fig 15. Maximum Avalanche Energy vs. Temperature
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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 T_jmax. This is validated for
every part type.
2. Safe operation in Avalanche is allowed as long asT_jmax is
not exceeded.
3. Equation below based on circuit and waveforms shown in
Figures 17a, 17b.
4. P_{D (ave)} = Average power dissipation per single
avalanche pulse.
5. BV = Rated breakdown voltage (1.3 factor accounts for
voltage increase during avalanche).
6. I_av = Allowable avalanche current.
7. ∆T = Allowable rise in junction temperature, not to exceed
T_jmax (assumed as 25°C in Figure 14, 15).
t_{av =} Average time in avalanche.
D = Duty cycle in avalanche = t_av ·f
Z_thJC(D, t_av) = Transient thermal resistance, see figure 11)
P_{D (ave)} = 1/2 ( 1.3·BV·I_av) = DT/ Z_thJC
I_av = 2DT/ [1.3·BV·Z_th]
E_{AS (AR)} = P_{D (ave)}·t_av
5