4

Application Considerations for SiC MOSFETs

January 2011

CPWR-AN08, REV -

Application Considerations for SiC MOSFETs -

January 2011

This document is provided for informational purposes only and is not a warranty or a specification.

For product specifications, please see the data sheets available at www.cree.com/power. For warranty

information, please contact Cree Sales at PowerSales@cree.com.

ramifications of the modestly higher gate voltage and lower gate charge can be reconciled by using the

product of gate charge and gate voltage as a metric of gate energy. The

comparison is shown in Figure 4. Even though the operating conditions are not exactly matched, the

results of this comparison show that the

other devices. Therefore, the higher voltage swing does not adversely affect

is usually experienced with other gate controlled silicon devices.

observed in typical silicon MOSFETs and IGBTs. Once again, this is primarily due the mode

transconductance.

Gate Charge Comparison

Figure 4

A popular figure of merit when comparing

Minimization of the figure of merit is an indicator of

CMF20120D and the other Si MOSF

32.4

*nC. The figure of merit of the

kV part whereas the Si SJMOSFET is rated at only 900 V.

5

ramifications of the modestly higher gate voltage and lower gate charge can be reconciled by using the

product of gate charge and gate voltage as a metric of gate energy. The gate charge and gate energy

Even though the operating conditions are not exactly matched, the

results of this comparison show that the CMF20120D gate energy is comparable to or lower than the

the higher voltage swing does not adversely affect gate drive power

is usually experienced with other gate controlled silicon devices. The Miller plateau is not as flat as

observed in typical silicon MOSFETs and IGBTs. Once again, this is primarily due the mode

Gate Charge Comparison

Gate Energy Comparison

Figure 4: Gate charge and energy comparison

of merit is an indicator of the superior part. A comparison between the

and the other Si MOSFETs is shown in Figure 5. The Si SJMOSFET has a figure of merit of

. The figure of merit of the CMF20120D is 7.12

*nC. Furthermore, the CMF20120D

SJMOSFET is rated at only 900 V.

1.75

2.09

2.57

0

1

2

3

4

5

6

ramifications of the modestly higher gate voltage and lower gate charge can be reconciled by using the

gate charge and gate energy

Even though the operating conditions are not exactly matched, the

comparable to or lower than the

gate drive power

versus gate charge characteristics are somewhat different from what

is not as flat as

observed in typical silicon MOSFETs and IGBTs. Once again, this is primarily due the modest amount of

Gate Energy Comparison

and total gate charge [6].

A comparison between the

as a figure of merit of

CMF20120D is a 1.2

2.70

5.44