“To prevent a short-circuit in the upper and lower arms, it is necessary to set an on-off timing delay between the different arms. During the so called ‘dead time’ period both devices are switched off.
For details, refer to Chapter 7.3 of IGBT Module Application Manual.”
FAQ Categories: Power MOSFET
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What is the dead time?
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Where can we obtain the latest version of data sheets?
The data sheets can be downloaded from Fuji Electric web site. The use of parametric search is recommended. Please contact Fuji Electric Corp. of America or your local sales representative or distributor to answer your question.
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Why do the currents balance if IGBTs with positive temperature coefficients are connected in parallel?
“Let’s consider the case where two IGBTs with different VCEsat are connected in parallel.
(1) A larger amount of the current will flow through the IGBT with smaller VCEsat.
(2) Due to the larger current flow, the total loss of the IGBT becomes large and the junction temperature increase.
(3) If the IGBT has a positive temperature coefficient, VCEsat increases with increasing junction temperature Tvj and hence, the current will decrease until current balance is achieved.” -
How can we reduce radiation noise?
Radiation noise can be reduced through methods such as reducing the loop current area where noise is generated, or adjusting the gate resistance. For details, refer to IGBT’s Application Manual Chapter 10.
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How can we reduce conductive noise?
“Conductive noise can be reduced through methods such as adding an LC filter on the AC power side, adding a ferrite core, or adjusting the gate resistance to suppress dv/dt at the time of switching.
For details, refer to IGBT’s Application Manual Chapter 10.” -
What types of noise are generated at an inverter unit that has a power semiconductor device built in?
There are two types of noise: conductive noise (noise terminal voltage) and radiation noise. Conductive noise propagates over a conductor or earth wire in a main circuit. It is divided into two groups: normal mode and common mode. Radiation noise is generated within a device and emitted into the air because the device wiring or casing works as an antenna. For details, refer to IGBT’s Application Manual Chapter 10.
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Have Fuji semiconductor parts an UL certification?
Power semiconductor modules of Fuji Electric Corp. of America have been certified with UL standard 1557, category code QQQX2 (File No. E82988). The relevant model types can be found on the UL website’s (http://japan.ul.com/) Online Certifications Directory.
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Are Fuji semiconductor parts compliant with REACH regulations?
Please contact Fuji Electric Corp. of America or your local sales representative or distributor to answer your question.
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Where can we obtain an RoHS Certificate of Conformity (CoC)?
Please contact Fuji Electric Corp. of America or your local sales representative or distributor to answer your question.
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Is there any quick way to determine the quality of IGBT before mounting?
You can verify the IGBT by checking the leakage current between G and E, and C and E, using a transistor curve tracer (CT). Simple failure diagnosis can also be done using a voltage, resistance tester in place of a CT. For details, refer to Application Manual Chapter 4-2.
