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I'm implementing a 300V MOSFET H Bridge with IR2110 driver.IR 2110 H Bridge and Control Signnal I decided to first try it in low (and safe) voltages, thus replacing the 300V with 12V as shown in the diagram. The MOSFETs I'm using are P20NM60FP, with a VGS of 5V. Ideally, I should have this waveform at output load Ideal output

I've checked every connection and the control signal from my microcontroller is correct (5V high, 1 Hz frequency). However, when I tried it, I get this spiky waveform as a result. Any ideas as to why is this happening? Actual output

Emi Ibañez
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1 Answers1

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Your o-scope time base is set to 1.00 seconds and, by the looks of it your control signals will be switching at 0.5 Hz. This is waaaaaaaaaaay too low in frequency. You have (in your driver circuit) bootstrap components that help give good drive signals to your upper N channel MOSFETs but, these bootstrap circuits can only work when you have sufficient drive frequency in your control signals. Try upping the frequency to 10 kHz.

enter image description here

I don't know what your expected operating frequency is but if it's higher than 10 kHz then run at that higher frequency. If you expect to run at 0.5 Hz or thereabouts, this circuit won't work. The circuit above needs tens of kHz to work properly.

Andy aka
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