H bridge problems using IR2110

Thread Starter

girvik123

Joined Jun 20, 2019
1
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!

IMG_20200806_164208.jpg


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IMG_20200806_165247.jpg
 

Alec_t

Joined Sep 17, 2013
11,517
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.
 

eetech00

Joined Jun 8, 2013
1,964
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.
 

ronsimpson

Joined Oct 7, 2019
819
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.

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