Electrical characteristics
Figure 12. Allowable IAV vs time in avalanche
STD60NF55LA
The previous curve gives the safe operating area for unclamped inductive loads, single
pulse or repetitive, under the following conditions:
PD(AVE) = 0.5* (1.3*BVDSS*IAV)
EAS(AR) = PD(AVE)*tAV
Where:
IAV is the allowable current in avalanche,
PD(AVE) is the average power dissipation in avalanche (single pulse)
tAV is the time in avalanche.
To derate above 25°C, at fixed IAV, the following equation must be applied:
IAV=2*(Tjmax-TCASE) / (1.3*BVDSS*Zth)
Where:
Zth= K*Rth is the value coming from normalized thermal response at fixed pulse width equal
to TAV
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