DocID024196 Rev 1

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AN4242

Efficiency measurement

4

Efficiency measurement

Table 4 summarizes the key parameters for the 1st and 2nd generation of SiC diodes. If the

JBS structure improves the surge current capability, it degrades somewhat the values of

forward voltage drop at low current level.

In a typical PFC application, the efficiency will be affected by less than 0.1% between the

1st and 2nd generation.

A first approximation demonstrated by the following equations shows that the efficiency

difference in a PFC could be estimated by

V

Equation 26

with

Equation 27

and

Equation 28

then

Equation 29

with

Equation 30

Table 4. Comparison of key parameters between first generation and second

generation of SiC diodes

Product

sinusoidal, 10 ms

typical / maximum

typical / maximum

6 A SiC, 1st gen

STPSC606D

600

27

1.4 / 1.7

1.6 / 2.1

6 A SiC, 2nd gen

STPSC6H065D

650

60

1.5 / TBD

1.9 / TBD

V· Iav + R · I

t0

d

rms

2

V· I

out

out

=

I=

av

Ö

I=

rms

2

3 ·

· V

p

out

·

V

+ k · I

· R

t0

av

d

V· I

out

out

=

=

k =

V

· 16

out

2

·

h