IRFP3006PbF

5

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© 2013 International Rectifier

September 06, 2013

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.

5. BV = Rated breakdown voltage (1.3 factor accounts for voltage

increase during avalanche).

7.

T = Allowable rise in junction temperature, not to exceed Tjmax

(assumed as 25°C in Figure 14, 15).

D = Duty cycle in avalanche = tav ·f

25

50

75

100

125

150

175

Starting TJ , Junction Temperature (°C)

0

100

200

300

400

TOP

Single Pulse

BOTTOM 1% Duty Cycle

ID = 170A

Fig 15.

Maximum Avalanche Energy vs. Temperature

Fig 14.

Typical Avalanche Current vs. Pulsewidth

1E-006

1E-005

0.0001

0.001

0.01

0.1

t1 , Rectangular Pulse Duration (sec)

0.0001

0.001

0.01

0.1

1

0.20

0.10

D = 0.50

0.02

0.01

0.05

SINGLE PULSE

( THERMAL RESPONSE )

Notes:

1. Duty Factor D = t1/t2

2. Peak Tj = P dm x Zthjc + Tc

1.0E-06

1.0E-05

1.0E-04

1.0E-03

1.0E-02

1.0E-01

tav (sec)

1

10

100

1000

0.05

Duty Cycle = Single Pulse

0.10

Allowed avalanche Current vs avalanche

pulsewidth, tav, assuming

 j = 25°C and

Tstart = 150°C.

0.01

Allowed avalanche Current vs avalanche

pulsewidth, tav, assuming

Tj = 150°C and

Tstart =25°C (Single Pulse)

Fig 13.

Maximum Effective Transient Thermal Impedance, Junction-to-Case