IR2110 test circuit problem

Hi!
I'm trying to test a drive circuit with IR2110 IC for a IGBT module but I'm having some problems.
The control signal is ok in the HIN and LIN but I'm getting nothing in between HO and VS or between LO and COM.
I didn't connect the COM to ground because I'll use a Neutral-Point-Clamped arm and I don't want to make a connection between the four IGBT emitter. The frequency of the input signals is 5kHz, by the way.
I attached the test circuit I'm using.

joelmarinho said:

Hi!
I'm trying to test a drive circuit with IR2110 IC for a IGBT module but I'm having some problems.
The control signal is ok in the HIN and LIN but I'm getting nothing in between HO and VS or between LO and COM.
I didn't connect the COM to ground because I'll use a Neutral-Point-Clamped arm and I don't want to make a connection between the four IGBT emitter. The frequency of the input signals is 5kHz, by the way.
I attached the test circuit I'm using.

Click to expand...

Please attach the schematics

I didn't connect the COM to ground because I'll use a Neutral-Point-Clamped arm and I don't want to make a connection between the four IGBT emitter.

Click to expand...

The ground connection is required.
Please consult the IR2110 application notes about permitted voltage differences between pins.

Besides the required DC path between COM and VSS, the high side driver won't work without a means to charge the bootstrap capacitor or a respective static power supply.

To clarify about the actual voltage potentials, you should show a complete schematic including all external power supply connections.

I doubt that IR2110 will work for the intended inverter topology. A principle schematic would help, too.

Thanks, FvM.
Can you advice me others IGBT drive ICs for my inverter topology (Neutral-Point-Clamped)?

Opto-islolated gate drivers can always work, but they require multiple/multi-channel isolated power supplies.