[SOLVED] IR2110 HO output not follows input duty cycle

Hi,
I got a problem using IR2110 to drive a pair of IRF540N MOSFETs. The output of the IR2110 HO is not what I expected.
Here is my schematic:


When I change the input duty cycle for HO, only the top portion of the waveform change but not the lower portion.

38% duty cycle (blue is HO, purple is LO)


46% duty cycle (blue is HO, purple is LO)


I'm using TL494 to drive the IR2110.

Please help me on this problem, thank you.

Better to use TLP250 ( opto-coupler) and complementry Transistor configuation befor the gate of Mosfet will help you out your duty cycle resolve problem here is problem while firing the MOSFET....read more about it ......
**broken link removed**
regards,

Milind

Are you driving both the HIN and LIN inputs with the same duty cycle? If so, I think what you're seeing is reasonable. The part of the waveform you circled is when HIN goes from high to low and LIN stays low. In that case the output of the H bridge (the voltage at Vs) is not really defined, and it may settle to some voltage between your supply voltage and GND. To confirm whether things are working correctly, look at the HO voltage with respect to VS, not GND. That should show a square wave with the correct shape.

milind.a.kulkarni said:

Better to use TLP250 ( opto-coupler) and complementry Transistor configuation befor the gate of Mosfet will help you out your duty cycle resolve problem here is problem while firing the MOSFET....read more about it ......
**broken link removed**
regards,

Milind

Click to expand...

I really doubt his "issue" is with the drive strength of the IR2110. I don't think there's really an issue at all.

Clement10 said:

Hi,
I got a problem using IR2110 to drive a pair of IRF540N MOSFETs. The output of the IR2110 HO is not what I expected.
Here is my schematic:
View attachment 63816

When I change the input duty cycle for HO, only the top portion of the waveform change but not the lower portion.

38% duty cycle (blue is HO, purple is LO)
View attachment 63817

46% duty cycle (blue is HO, purple is LO)
View attachment 63818

I'm using TL494 to drive the IR2110.

Please help me on this problem, thank you.

Click to expand...

Is duty cycle of H-bridge output changed by increasing or decreasing of deadtime between two PWM signal? Or only way to change output duty cycle is changing the duty cycle of input signals?

Clement10 said:

Hi,
I got a problem using IR2110 to drive a pair of IRF540N MOSFETs. The output of the IR2110 HO is not what I expected.
Here is my schematic:
View attachment 63816

When I change the input duty cycle for HO, only the top portion of the waveform change but not the lower portion.

38% duty cycle (blue is HO, purple is LO)
View attachment 63817

46% duty cycle (blue is HO, purple is LO)
View attachment 63818

I'm using TL494 to drive the IR2110.

Please help me on this problem, thank you.

Click to expand...

what about the Vs-COM signal? Can you post it too?