Hello,

I designed attached circuit to drive H Bridge. My generated input signals are in attached picture, duty cyce that I am using is 40% for each signal, 99 kHz frequency. As result I am getting really bad shape of signal on R9 resistor. I am no getting steep signal when I turning H bridge off. I did mistake in schematics that I am getting this disturbed signal?

Thank you!

 

You perhaps need to tidy up your schematic around IC2 it looks like IC2 Hin and LIN are connected to IC1.

 

Links
http://tahmidmc.blogspot.com/2013/01/using-high-low-side-driver-ir2110-with.html
https://www.silabs.com/support/isolation-bootstrap-calculator

Max.

 

Are you providing any dead-time between Hin and Lin, to avoid shoot-through? Shoot-through might result in Vcc being pulled down and hence transients.

 

Hello,

I designed attached circuit to drive H Bridge. My generated input signals are in attached picture, duty cyce that I am using is 40% for each signal, 99 kHz frequency. As result I am getting really bad shape of signal on R9 resistor. I am no getting steep signal when I turning H bridge off. I did mistake in schematics that I am getting this disturbed signal?

Thank you!

View attachment 214612


View attachment 214614
View attachment 214613

Is the upper scope the signals your are feeding to the controllers? If so, looks like there is dead time judging from the upper scope image. The signal should be kept separate to each pair of the controller inputs.
Otherwise, seems the mosfets are not turning off fast enough. Might try lowering the value of the gate resistors and/or the gate pull down resistors.

 

I am getting really bad shape of signal on R9 resistor.

You are getting what you asked for.
What do you want the signal to look like?
During dead time all MOSFETs are off. R9 is just floating. Not connected to anything. During dead the voltage can be anywhere from ground to VCC and often at 1/2 supply. You can see both ends of R9 have slow sloppy edges that are heading for 1/2 supply. There will be some ringing. If R9 was a motor the signal will look different. A inductive load will look different.