I have the microphone amplifier and line Powerpod 410 R that after an analysis I found that one of the output mosfets is in total short. The short mosfet is this IRFB23N20D, however I don't find it in my country Brazil, but I found this IRFB4227PbF. As I am new to amplifiers using mosfet, I asked for help, I have been reading the datashet of one and the other has some differences as the current supported my question is will I have problems replacing what I found in my country?


OBSERVATION: I'm sorry I use google translator, so I may not express myself well.

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    \$\begingroup\$ The link to the first MOSFET is down. We would need schematics of the Powerpod 410 R to make any decisions, or suggestions. \$\endgroup\$
    – user105652
    Aug 16, 2020 at 4:00
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    \$\begingroup\$ ”I don't find it in my country X” Digi-Key, Mouser, Farnell ships all over the world except North Korea. \$\endgroup\$
    – winny
    Aug 16, 2020 at 12:13
  • \$\begingroup\$ Okay, I already added the schematic on the post fixed the first link in the mosfet. The problem is the delay when any order arrives stays more than 1 month at customs. I can try to see some others but the closest I found was this one. \$\endgroup\$ Aug 16, 2020 at 15:19

1 Answer 1


The IRFB4427 has lower ON resistance, but very high input/output capacitances. In a Class D audio amplifier, I would not replace the IRFB23N20 with it. Instead, you can use MOSFETs with similar I/O capacities and currents. (IRFB4020, IRFB5620, FQP19N20, RCX200N20)

  • \$\begingroup\$ You never really know what you're getting from aliexpress. I would recommend rather looking for devices with similar capacitances, because you definitely have a point that high FET capacitance would be a problem in a class-D amplifier. \$\endgroup\$
    – Hearth
    Aug 16, 2020 at 11:40
  • \$\begingroup\$ In ali. i do not trust buy semi conductors there \$\endgroup\$ Aug 16, 2020 at 15:18
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    \$\begingroup\$ You can also shop here quickly. \$\endgroup\$
    – csabahu
    Aug 16, 2020 at 21:23
  • \$\begingroup\$ I'll wait for someone to see if I can use the one I found here, otherwise I care. Added schematic of amplifier in post \$\endgroup\$ Aug 17, 2020 at 3:23
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    \$\begingroup\$ I see the difference in loss is 1.8W due to the higher resistance. So this is not significant. (The switching current is approx. 6A.) \$\endgroup\$
    – csabahu
    Aug 17, 2020 at 17:28

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