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MOSFET (Si/SiC) Forum Discussions

User20208
Level 1
First question asked
Level 1
Hi,

A N-Channel Mosfet when in the on-state and no drain/load current flowing, the Vds voltage would be zero (i.e differential voltage across drain and source). At this point, when a load connected to mosfet's source is switched on by an external switch would draw a 50A of DC current. How to interpret the SOA curve
at these conditions when drain/load current begins to flow and Vds (voltage Vds = 0V, i.e 48V on either side as an example)

Example mosfet: https://www.infineon.com/dgdl/Infineon-IPB017N10N5-DataSheet-v02_05-EN.pdf?fileId=5546d4624a75e5f101...

Can any one help me explaining how to interpret the SOA curve?

Thanks for the help.
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1 Solution
G_Anshika
Moderator
Moderator 100 replies posted 50 solutions authored 100 sign-ins
Moderator

Hello,

Thank you for posting on Infineon Community.

The safe operating area is the voltage and current conditions over which a MOSFET operates without permanent damage or degradation. The MOSFET must not be exposed to conditions outside the safe operating area, even for an instant. Therefore, it is necessary to determine whether the operating locus of the MOSFET is within the safe operating area.
There are five limit-lines defining the SOA diagram are the RDS(on) limit-line (blue line), the current limit-line (red line), the maximum power limit-line(dark green line), the thermal instability limit-line (light green line) and the breakdown voltage limit-line (yellow line).

G_Anshika_0-1643903087862.png

Within these limit-lines the green shaded area gives the area where the MOSFET can be safely operated.


1. RDS(on)-limit-line (blue line)
2. Package-limit-line (red line)
3.Maximum-power-limit-line
4. Thermal (in-)stability limit-line
5. Breakdown voltage limit-line

Please refer to this Application Note for more details:
Infineon-ApplicationNote_Linear_Mode_Operation_Safe_Operation_Diagram_MOSFETs-AN 
I hope this helps. 

Thanks and Regards,
Anshika
                                

View solution in original post

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User270
Level 5
5 solutions authored First solution authored
Level 5
Please see page 9 in the following app note.
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G_Anshika
Moderator
Moderator 100 replies posted 50 solutions authored 100 sign-ins
Moderator

Hello,

Thank you for posting on Infineon Community.

The safe operating area is the voltage and current conditions over which a MOSFET operates without permanent damage or degradation. The MOSFET must not be exposed to conditions outside the safe operating area, even for an instant. Therefore, it is necessary to determine whether the operating locus of the MOSFET is within the safe operating area.
There are five limit-lines defining the SOA diagram are the RDS(on) limit-line (blue line), the current limit-line (red line), the maximum power limit-line(dark green line), the thermal instability limit-line (light green line) and the breakdown voltage limit-line (yellow line).

G_Anshika_0-1643903087862.png

Within these limit-lines the green shaded area gives the area where the MOSFET can be safely operated.


1. RDS(on)-limit-line (blue line)
2. Package-limit-line (red line)
3.Maximum-power-limit-line
4. Thermal (in-)stability limit-line
5. Breakdown voltage limit-line

Please refer to this Application Note for more details:
Infineon-ApplicationNote_Linear_Mode_Operation_Safe_Operation_Diagram_MOSFETs-AN 
I hope this helps. 

Thanks and Regards,
Anshika
                                

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