I'm currently reverse-engineering an air conditioner inverter circuit.

I have stumbled upon a weird package.

The thing is I can't de-solder this component, so I can't read the letters on it.

Do you know what this is?

Since it's connected to the capacitor, it might be a full-bridge rectifier, but I couldn't say for sure. A part number or a datasheet would be very helpful.

edit - hey guys, I think it's time to let it go. You can't possibly reverse engineer everything you see. I've learned it the hard way. But also I've learned so much more about power electronics along the way. I guess that what actually matters. Search for "Intelligent Power Module" for to learn about this "inverters" and "High efficient BLDC motor Drivers" if you interested. I have lost so much time because I didn't know that particular Word. Thanks everyone.

photo of PCB

photo of PCB

  • \$\begingroup\$ yeah that seems plausable, \$\endgroup\$ Apr 1, 2021 at 7:16
  • \$\begingroup\$ My guess is there is two motor drives - the fan and the compressor. So I’d say it is a mosfet/igbt triple phase driver module. \$\endgroup\$
    – Kartman
    Apr 1, 2021 at 7:32
  • \$\begingroup\$ @Kartman yeah but that's on the Left (take a look at the 1st picture). as you can see in the last pic, it's the 3 Phase output(UVW) right above that IGBT package. even if, this one is also an IGBT package, then where is the rectifier? \$\endgroup\$ Apr 1, 2021 at 7:39
  • \$\begingroup\$ Is this on the input line and neutral, or the output? You call it an inverter, so I would assume DC to AC conversion is going on somewhere in here. \$\endgroup\$
    – Hearth
    Apr 1, 2021 at 13:25
  • \$\begingroup\$ @Hearth This is an Split air conditioner Inverter, it converts Single Phase AC in to DC and then convert into 3 Phase AC (aka BLDC motor driver). Single Phase ---> HVDC--->3 Phase \$\endgroup\$ Apr 1, 2021 at 14:35

1 Answer 1


It seems like an IGBT (or similar) three phase bridge module. Usually something like 6 IGBT thermally bonded to efficiently drive a 3-phase motor. Often they have nice features like thermal sensors and integrated gate drive (optimized for the transistors). Search for 3-phase IGBT pack or something like that, Semikron does some nice ones for example (but many other too, look at Infineon, On Semi, etc)

  • \$\begingroup\$ already did that but no luck on that. the thing is, If that's an IGBT package, where is the Rectifier? this circuit has big'ol electrolytic caps, and the power source for this Board is single phase AC.so this board diffo need a AC to DC conversion \$\endgroup\$ Apr 1, 2021 at 7:49

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