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I am using EG8010 chip to create a 400V DC to 220AC inverter which does not use bulky transformers. I have used the exact same circuit shown in the data sheet of EG8010. The circuit works ok and output a good sine wave for low input voltages (I have tested it upto 80V). When I input 400V's however, the circuit seem to be very unstable and for no apparent reason, MOSFET's gets damaged. This happens even if there is no load connected to the output. The MOSFET's I am using are the ones recommended in the datasheet (IRF840) which have 500V mas VDS.

I've read in a different forum that this could be due to voltage spikes due to inductance of the load (for example the filter inductor). Could this be the case? If so, what would be the best solution avoid such spikes?

Schematics: https://www.lz2gl.com/data/power-inverter-3kw/eg8010_datasheet_en.pdf Please refer to Figure 6‐2 in that doc.

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    \$\begingroup\$ Plenty of room for speculations, please provide schematics and signal screen shots of the working unit at 80 V. A picture of the device often can help as well \$\endgroup\$
    – Jens
    Jun 14, 2022 at 18:47
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    \$\begingroup\$ Using a 500Vds MOSFET with inductors at 400V is like taking a Yugo onto the Autobahn and wondering why it dies at 150km/h. i.e. for real-world performance, at least double the ratings is a really good idea. \$\endgroup\$
    – rdtsc
    Jun 14, 2022 at 18:53
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    \$\begingroup\$ ”The MOSFET's I am using are the ones recommended in the datasheet (IRF840) which have 500V mas VDS.” Ouch! Think 700+ V. \$\endgroup\$
    – winny
    Jun 14, 2022 at 19:54
  • \$\begingroup\$ The physical layout of the circuit is as important as the schematic. Post detailed high resolution pictures of your assembled PCB. \$\endgroup\$ Jun 14, 2022 at 22:48
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    \$\begingroup\$ There is no bus link capacitor shown. Should be one with several hundred uF and one or more low impedance film types. \$\endgroup\$
    – PStechPaul
    Feb 19, 2023 at 23:43

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