DocID024196 Rev 1

17/26

AN4242

New 650 V JBS SiC diodes

Current stresses in the range of tens of microseconds are usually linked to the switching

period. Such a surge current can also happen during lightning surge tests. Stresses in the

range of tens of milliseconds are usually related to line-dropout tests.

3.3

The efficiency of the JBS structure to sustain a current spike is linked to the bias current

level of the merged PN junction. This level characterizes “the JBS positioning”. Designing

the diode with a higher bias current level leads to a higher forward voltage drop, and hence

forward voltage drop at high current. However, the conduction of a PN junction implies some

carriers’ recombination, which does not happen in a conventional SiC Schottky structure. As

3.3.1

Forward characteristics comparison between ST’S SiC 2nd generation

and other JBS designs

Figure 15 illustrates in dotted lines another dimensioning of the merged PN junction

compared with ST’s design. The dotted lines present forward voltage drops around 2 volts

higher than ST’s diode between 30 A and 70 A at 225 °C. On the other hand, this

forward current levels.

Figure 15. Forward voltage drop between STPSC6H065D and another JBS structure

generation

468

10

SiC 1st generation

14

27

30

40

SiC 2nd generation

38

60

75

90

25 °C

225 °C

STPSC6H065D 2G

75 °C

125 °C

175 °C

V

020

30

40

50

60

10

70

80

90

100

IF (A)

VF (V)

8

7

6

5

4

3

2

1

0

9

10

11

Other JBS technology