@asdf44 & @KlausST: I was posting wrong (OLD) schematic. Actual circuit has that integrated into design.
@KlausST: According to your answer in this thread (
https://www.edaboard.com/showthread.php?362476-IR2113-Mosfet-driver&highlight=ir2113):
Re: IR2113 Mosfet driver
Hi, don´t measure HO wrt GND --> measure HO wrt VS. Is it still equal?
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I tried that. The signal is basically the same.
Question: So was I basically shorting Vs and GND through the oscilloscope?
@Easy peasy: the input waveforms from function generator are 180 degrees phase shifted squarewaves and are fed on IR2113. On gates the time period of the signal on the upper MOSFETs is somewhat changed. @4kHz there is this slope (of which I am mainly concerned about) but time period remains the same and @19kHz slope remains and time period lenghtens.
@Fvm: I use Hantek 6022BE with x10 probes and mistake comes from not selecting right probe settings in software and picture printout which does not show grid. Since grid of osciloscope isn't displayed, you cannot see divisions. 5xtick=one division -> 6xtick -> 12V @ 12V/div. Should I use AC coupling oscilloscope? Or is it quite the same result if I measure from VS to HO? At least based on my understanding it would be the same.
@fourtytwo:
1) Are they a must be? And where(Power supply, close to IR2113, anywhere else? Decoupling capacitors are mainly implemented to compensate for stray inductances, right? I'd appreciate good read on decoupling, I googled but didn't get the answers, that would help me give a good estimate of values. For power supplies or voltage regulators 100uF,100nF parallel was often mentioned. Are 100uF && 100nF parallel good selection?
2) All diodes are UF4007. I saw somewhere on forums that this is "slow" diode and shouldn't be used for arround 100kHz. They should definately handle 4kHz operation, don't you think? I was considering bootstrap circuit is causing problems, so I added resistance as AN-6076 suggests, tried various cap values but problems remains the same.
Value of bootstrap capacitor was calculated from AND9674/D(AN-6076) arround 100nF. KlausST suggested AN-978. UF4007 are parallel with gate resistor.
3) These resistors are suggested for achieving higher frequencies(which I am after) and also to minimize switching losses.
4) Also crossed my mind. Due to safety precautions and in lack of 300V DC supply I tried 12V for rail supply. I figured when this will work I will step up. I am currently supplying 5V and 12V from computer power supply and voltage rail from adapter 230VAC/12VDC@2A. Sh
Really appreciate the help, but my mind was also boggled by similar remarks. It could also be function generator circuit. It comes from DDS, which outputs "main" signal and inverted signal, is amplified through summing amplifier and then fed to IR2113. There is basically no "dead time" between LO and HI signal change. Is this a problem, or should
IR2113 handle that?
I have not yet tried different diodes, decoupling caps and didn't yet improve the layout, was hoping to improve layout once I get better results.
I will make new PCB from scratch, perhaps I miss-looked something.