May 25, 2021
02:03 AM
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May 25, 2021
02:03 AM
Hello,
Why does the collector current at high temperature get lower than that at low temperature after a certain value of V_GE?
For instance, as shown in the transfer characteristic curve, Ic, at V_GE below 7.5V, is higher at 150°C than at 25°C. While as V_GE goes above 7.5V 150°C curve has lower Ic value than the 25°C curve.
Thank you!
Why does the collector current at high temperature get lower than that at low temperature after a certain value of V_GE?
For instance, as shown in the transfer characteristic curve, Ic, at V_GE below 7.5V, is higher at 150°C than at 25°C. While as V_GE goes above 7.5V 150°C curve has lower Ic value than the 25°C curve.
Thank you!
Solved! Go to Solution.
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- IFX
1 Solution
May 27, 2021
07:47 AM
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May 27, 2021
07:47 AM
Hi Lisa,
the reason of this behavior is related to two different contribution of the IGBT voltage drop, one comes from the channel resistance of the MOS structure and the other comes from the voltage drop in the drift zone.
It is very important to guarantee that the IGBT works well inside the region with negative temperature coefficient, especially in applications where multiple devices are parallelized, because it guarantees that the current sharing between the devices is always uniform. In the case of the device in your example, the ZTC is at VGE=7.5V and this is the reason why the recommendation is to operate the device with a VGE that is much higher than 7.5V.
I hope that this helps.
Best Regards,
Giuseppe De Falco
the reason of this behavior is related to two different contribution of the IGBT voltage drop, one comes from the channel resistance of the MOS structure and the other comes from the voltage drop in the drift zone.
- For 'low' VGE, the main contribution of the voltage drop comes from channel resistance, and it has a positive dependence with the temperature (that means that at high temperature the device carries more current for the same VCE).
- At 'high' VGE, the effect of the drift zone resistance becomes predominant, and this has a negative temperature coefficient (that is, at high temperature the device carries less current for the same VCE).
It is very important to guarantee that the IGBT works well inside the region with negative temperature coefficient, especially in applications where multiple devices are parallelized, because it guarantees that the current sharing between the devices is always uniform. In the case of the device in your example, the ZTC is at VGE=7.5V and this is the reason why the recommendation is to operate the device with a VGE that is much higher than 7.5V.
I hope that this helps.
Best Regards,
Giuseppe De Falco
1 Reply
May 27, 2021
07:47 AM
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May 27, 2021
07:47 AM
Hi Lisa,
the reason of this behavior is related to two different contribution of the IGBT voltage drop, one comes from the channel resistance of the MOS structure and the other comes from the voltage drop in the drift zone.
It is very important to guarantee that the IGBT works well inside the region with negative temperature coefficient, especially in applications where multiple devices are parallelized, because it guarantees that the current sharing between the devices is always uniform. In the case of the device in your example, the ZTC is at VGE=7.5V and this is the reason why the recommendation is to operate the device with a VGE that is much higher than 7.5V.
I hope that this helps.
Best Regards,
Giuseppe De Falco
the reason of this behavior is related to two different contribution of the IGBT voltage drop, one comes from the channel resistance of the MOS structure and the other comes from the voltage drop in the drift zone.
- For 'low' VGE, the main contribution of the voltage drop comes from channel resistance, and it has a positive dependence with the temperature (that means that at high temperature the device carries more current for the same VCE).
- At 'high' VGE, the effect of the drift zone resistance becomes predominant, and this has a negative temperature coefficient (that is, at high temperature the device carries less current for the same VCE).
It is very important to guarantee that the IGBT works well inside the region with negative temperature coefficient, especially in applications where multiple devices are parallelized, because it guarantees that the current sharing between the devices is always uniform. In the case of the device in your example, the ZTC is at VGE=7.5V and this is the reason why the recommendation is to operate the device with a VGE that is much higher than 7.5V.
I hope that this helps.
Best Regards,
Giuseppe De Falco