IR2110 High-Side Output Shows Voltage When Idle

developement
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Hello everyone. I’m working on a project with the IR2110 and using inline current sensing with a 6-MOSFET inverter. On the IR2110, I’m seeing a voltage close to 5V on the high-side output while the input is idle (i.e., not driven), and this bothers me. However, when I apply a PWM signal, the high-side output correctly switches between 12V and 0V as expected.

Why does the IR2110 leak a certain voltage on the high-side output when the input is idle or not driven? Has anyone experienced something like this before? I can’t share the schematic for specific reasons. I know it sounds weird, but I’m hoping someone might have an idea.

For current sensing, I’m using the bidirectional TSC2012IST op-amp. When idle, the current sense output seems to read above 2.2V, whereas I would expect it to be around 1.65V. Could this be related?

Thanks in advance!

2 Answers

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The Datasheet for the IR2110 does mention it has Schmitt Trigger inputs with pull down, but I guess in your case it’s not working, or the pull-down is too weak.
Since Hi-Z or unpowered input is not a valid input state anyways, why not ensure that it does not happen by including an external pull down resistance to make sure to always have a well defined input state?

You're right in what you said, and I'd like to try this—I hope it works. Actually, there's already a PCB design, so I need to see if it's possible to add it and test it. If not, the dsPIC33 series microcontroller should have such a feature built in anyway.

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Hi sir

Did you find a solution for this problem

I think its a normal situation because vs is floating and it swings around depending on the load resistance