Aug 22, 2019
07:15 AM
- Mark as New
- Bookmark
- Subscribe
- Mute
- Subscribe to RSS Feed
- Permalink
- Report Inappropriate Content
Aug 22, 2019
07:15 AM
Hello again, can you also tell me what the dependence of short-circuit capability with bus voltage, gate voltage and temperature is? Thanks in advance!
Solved! Go to Solution.
- Tags:
- IFX
1 Solution
Sep 05, 2019
12:16 AM
- Mark as New
- Bookmark
- Subscribe
- Mute
- Subscribe to RSS Feed
- Permalink
- Report Inappropriate Content
Sep 05, 2019
12:16 AM
Hi AnniLe,
some details on SC (e.g. example waveform) you can find in the following Application note:
https://www.infineon.com/dgdl/Infineon-Introduction_to_CoolSiC_1200V_SiC_MOSFET-ApplicationNotes-v01...
SC withstand time will be significantly reduced for gate voltages above 15 V. Therefore for applications needed SC capability we are recommending to use 15 V gate voltage, whereas applications not needing SC capability
Lower DC-link voltage will increase SC withstandtime approximately inverse proportional
Lower junction temperature before SC will give a slight increase in SC withstand time.
Best regards,
electricuwe
some details on SC (e.g. example waveform) you can find in the following Application note:
https://www.infineon.com/dgdl/Infineon-Introduction_to_CoolSiC_1200V_SiC_MOSFET-ApplicationNotes-v01...
SC withstand time will be significantly reduced for gate voltages above 15 V. Therefore for applications needed SC capability we are recommending to use 15 V gate voltage, whereas applications not needing SC capability
Lower DC-link voltage will increase SC withstandtime approximately inverse proportional
Lower junction temperature before SC will give a slight increase in SC withstand time.
Best regards,
electricuwe
4 Replies
Aug 26, 2019
02:13 AM
- Mark as New
- Bookmark
- Subscribe
- Mute
- Subscribe to RSS Feed
- Permalink
- Report Inappropriate Content
Aug 26, 2019
02:13 AM
The short-circuit time should derating with the bus voltage, gate voltage and temperature increase ,
Sep 05, 2019
12:16 AM
- Mark as New
- Bookmark
- Subscribe
- Mute
- Subscribe to RSS Feed
- Permalink
- Report Inappropriate Content
Sep 05, 2019
12:16 AM
Hi AnniLe,
some details on SC (e.g. example waveform) you can find in the following Application note:
https://www.infineon.com/dgdl/Infineon-Introduction_to_CoolSiC_1200V_SiC_MOSFET-ApplicationNotes-v01...
SC withstand time will be significantly reduced for gate voltages above 15 V. Therefore for applications needed SC capability we are recommending to use 15 V gate voltage, whereas applications not needing SC capability
Lower DC-link voltage will increase SC withstandtime approximately inverse proportional
Lower junction temperature before SC will give a slight increase in SC withstand time.
Best regards,
electricuwe
some details on SC (e.g. example waveform) you can find in the following Application note:
https://www.infineon.com/dgdl/Infineon-Introduction_to_CoolSiC_1200V_SiC_MOSFET-ApplicationNotes-v01...
SC withstand time will be significantly reduced for gate voltages above 15 V. Therefore for applications needed SC capability we are recommending to use 15 V gate voltage, whereas applications not needing SC capability
Lower DC-link voltage will increase SC withstandtime approximately inverse proportional
Lower junction temperature before SC will give a slight increase in SC withstand time.
Best regards,
electricuwe
Oct 21, 2019
10:29 PM
- Mark as New
- Bookmark
- Subscribe
- Mute
- Subscribe to RSS Feed
- Permalink
- Report Inappropriate Content
Oct 21, 2019
10:29 PM
Hello electricuwe,
sorry for my late response but thanks for your explanation and the hint to the application note! I've an additional question... how can a short circuit protection be provided for a SiC module with short circuit capability of 3µs?
Thanks
sorry for my late response but thanks for your explanation and the hint to the application note! I've an additional question... how can a short circuit protection be provided for a SiC module with short circuit capability of 3µs?
Thanks
Oct 23, 2019
06:01 AM
- Mark as New
- Bookmark
- Subscribe
- Mute
- Subscribe to RSS Feed
- Permalink
- Report Inappropriate Content
Oct 23, 2019
06:01 AM
Hi AnniLe,
at first please note that SC withstand time is rated differently for Discrete and module. Discrete devices are specified with 3 us, modules with 2 us. However, SC protection can be provided in both cases. There are two main challenges:
- delay time and tolerances of the detection circuit have to be minimized
- in some applications, e.g. drives, cable or load capacitance lead to significant current spike at every switching event. It has to be ensured that these current spikes do not lead to a SC turn off
For low power applications, SC detection via shunt in the DC- or in the source is feasible. As a fast comparator the comparator inside1ED44176N01F might be used:
https://www.infineon.com/dgdl/Infineon-1ED44176N01F-DS-v02_00-EN.pdf?fileId=5546d46265487f7b01655c2d...
See schematic in the application note:
https://www.infineon.com/dgdl/Infineon-EVAL-M5-E1B1245N-SiC-ApplicationNotes-v01_00-EN.pdf?fileId=55...
We are just updating the application note with test results on this.
For higher power desat-detection is more appropriate. Many newer driver ICs, especially the ones using non-optic isolation technology, have small delay time and tolerance and can be configured to detect an SC within approx. 1.5 us. One device suitable for this is the 1ED020I12-F2: https://www.infineon.com/dgdl/Infineon-1ED020I12-F2-DataSheet-v02_01-EN.pdf?fileId=db3a304330f686060...
Note that due to the fact that in a Mosfet there is no need to wait for conductivity modulation taking place like in an IGBT, shorter blanking times are possible for Mosfets
If the system uses Sigma-Delta current measurement in the output phases, a simple digital circuit can be implemented to observe if the datastream stays at 0 or 1 for more than approx. 1 us, indicating a SC condition.
Best regards,
electricuwe
at first please note that SC withstand time is rated differently for Discrete and module. Discrete devices are specified with 3 us, modules with 2 us. However, SC protection can be provided in both cases. There are two main challenges:
- delay time and tolerances of the detection circuit have to be minimized
- in some applications, e.g. drives, cable or load capacitance lead to significant current spike at every switching event. It has to be ensured that these current spikes do not lead to a SC turn off
For low power applications, SC detection via shunt in the DC- or in the source is feasible. As a fast comparator the comparator inside1ED44176N01F might be used:
https://www.infineon.com/dgdl/Infineon-1ED44176N01F-DS-v02_00-EN.pdf?fileId=5546d46265487f7b01655c2d...
See schematic in the application note:
https://www.infineon.com/dgdl/Infineon-EVAL-M5-E1B1245N-SiC-ApplicationNotes-v01_00-EN.pdf?fileId=55...
We are just updating the application note with test results on this.
For higher power desat-detection is more appropriate. Many newer driver ICs, especially the ones using non-optic isolation technology, have small delay time and tolerance and can be configured to detect an SC within approx. 1.5 us. One device suitable for this is the 1ED020I12-F2: https://www.infineon.com/dgdl/Infineon-1ED020I12-F2-DataSheet-v02_01-EN.pdf?fileId=db3a304330f686060...
Note that due to the fact that in a Mosfet there is no need to wait for conductivity modulation taking place like in an IGBT, shorter blanking times are possible for Mosfets
If the system uses Sigma-Delta current measurement in the output phases, a simple digital circuit can be implemented to observe if the datastream stays at 0 or 1 for more than approx. 1 us, indicating a SC condition.
Best regards,
electricuwe