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IRF7749L2PBF Datasheet, PDF (6/11 Pages) International Rectifier – RoHS Compliant, Halogen Free
IRF7749L2TR/TR1PbF
1000
Duty Cycle = Single Pulse
100
0.01
10
0.05
0.10
Allowed avalanche Current vs avalanche
1
pulsewidth, tav, assuming ΔΤ j = 25°C and
Tstart = 150°C.
Allowed avalanche Current vs avalanche
pulsewidth, tav, assuming ΔTj = 150°C and
Tstart =25°C (Single Pulse)
0.1
1.0E-06
1.0E-05
1.0E-04
1.0E-03
1.0E-02
1.0E-01
tav (sec)
Fig 15. Typical Avalanche Current Vs.Pulsewidth
280
TOP
Single Pulse
240
BOTTOM 1% Duty Cycle
ID = 120A
200
160
120
80
40
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 19a, 19b.
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. ΔT = Allowable rise in junction temperature, not to exceed
Tjmax (assumed as 25°C in Figure 15, 16).
tav = Average time in avalanche.
D = Duty cycle in avalanche = tav ·f
ZthJC(D, tav) = Transient thermal resistance, see figure 11)
PD (ave) = 1/2 ( 1.3·BV·Iav) = DT/ ZthJC
Iav = 2DT/ [1.3·BV·Zth]
EAS (AR) = PD (ave)·ta
+
‚
-

RG
6
D.U.T
+
ƒ
-
Circuit Layout Considerations
• Low Stray Inductance
• Ground Plane
• Low Leakage Inductance
Current Transformer
-„ +
• di/dt controlled by RG
• Driver same type as D.U.T.
VDD
+
• ISD controlled by Duty Factor "D"
-
• D.U.T. - Device Under Test
Driver Gate Drive
P.W.
Period
D=
P.W.
Period
* VGS=10V
D.U.T. ISD Waveform
Reverse
Recovery
Body Diode Forward
Current
Current
di/dt
D.U.T. VDS Waveform
Diode Recovery
dv/dt
VDD
Re-Applied
Voltage
Body Diode
IInndduuccttoorr CCuurrernetnt
Forward Drop
Ripple ≤ 5%
ISD
* VGS = 5V for Logic Level Devices
Fig 17. Diode Reverse Recovery Test Circuit for N-Channel HEXFET® Power MOSFETs
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