R0964LC10x to R0964LC12x

10.0 On-State Energy per Pulse Characteristics

These curves enable rapid estimation of device dissipation to be obtained for conditions not covered by

the frequency ratings.

Let Ep be the Energy per pulse for a given current and pulse width, in joules

Let Rth(J-Hs) be the steady-state d.c. thermal resistance (junction to sink)

and TSINK be the heat sink temperature.

Then the average dissipation will be:

( )WAV = EP ⋅ f and TSINK (max.) = 125 − WAV ⋅ Rth(J −Hs)

11.0 Reverse recovery ratings

(i) Qra is based on 50% Irm chord as shown in Fig. 1 below.

Fig. 1

(ii) Qrr is based on a 150µs integration time.

150 µs

∫i.e. Qrr = irr .dt

0

(iii)

K Factor = t1

t2

12.0 Reverse Recovery Loss

12.1 Determination by Measurement

From waveforms of recovery current obtained from a high frequency shunt (see Note 1, Page 5) and

reverse voltage present during recovery, an instantaneous reverse recovery loss waveform must be

constructed. Let the area under this waveform be E joules per pulse. A new heat sink temperature can

then be evaluated from:

( )TSINK (new) = TSINK (original ) − E ⋅ k + f ⋅ Rth(J −Hs )

where k = 0.227 (°C/W)/s

E = Area under reverse loss waveform per pulse in joules (W.s.)

f = rated frequency Hz at the original heat sink temperature.

Rth(J-Hs) = d.c. thermal resistance (°C/W).

Data Sheet. Types R0964LC10x to R0964LC12x Issue 2

Page 4 of 12

August, 2012