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[moved] problem with IR2118 mosfet driver in PSPICE.

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mohammadmother

mohammadmother

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Hi
I simulate this circuit in PSPICE
2118.png

but i get this error. I download the IR2118 PSPICE model.
error.png

please help!
 

Your timestep appears to be 5E-18. That is tiny. I believe you can try larger values. A reasonable starting value is so 1000 timesteps fit within one frequency cycle.
 

You know that the IR2118 circuit is incomplete? Missing bootstrap diode and capacitor.

Also the power circuit must be grounded.
 

Thanks for your help
I changed my circuit. However, this error yet exist.
2118.png

How I can change time step and insert bootstrap diode?

- - - Updated - - -

Excuse me I changed my circuit to this and error was solved
2118.png

But when the PWM is '1' (=when LIN='1'), the voltage between VB and HO is always 0. so the mosfet is off
 

Hi,

But when the PWM is '1' (=when LIN='1'), the voltage between VB and HO is always 0
Click to expand...
That's the way it works.

...the voltage between VB and HO is always 0. so the mosfet is off
Click to expand...
To be exact: A MOSFET is OFF, when the voltage between gate and source is 0.
What's this V_gs?

Klaus
 

I connect the driver pin according to the its datasheet.
Click to expand...
Not in the posted schematics.

In the latest schematic, when you added the bootstrap diode, you also mixed up the previously correct HO and VS connection.

Try once more.
 

Now, I changed my convert(boost instead of buck) driver and use IR2113.my circuit is :
2113.png

but I have this error :
error.png
 

Thanks, I do your work and the error was solved and vout appear. but the vout is 2 v (this is a boost converter!).
anyway I changed my converter to the buck to test your manner(my main target is driving P-mosfet with IR2113 in Buck converter). However the out put voltage was not correctbuck_IR2113.png. (we know in the P-channel mosfet the voltage of GS should be negative).

- - - Updated - - -

First I simulate this circuit without any driver.
buck_p-channel.png
 

IR2110 and similar drivers aren't design to drive PMOS transistors.

I must confess that I didn't completely realize the change form buck to boost converter, the ground referred transistor can be driven by a low-side driver without bootstrap circuit, the circuit suggested in post #9 should work nevertheless.
 

Thank you for your reply. but I'm really confused!
assume the converter is buck and the mosfet is N-channel. how we can driver it with IR2113?

Thanks a lot
 

Hi,

but the vout is 2 v (this is a boost converter!).
Click to expand...
I don´t see how this can be a boost converter.

Klaus
 

the boost is for former post.
Now I want to drive a buck converter with IR2113 and mosfet is N-channel . I want to use Bootstrap technique. My circuit is but I have error!:sad:

2113.png
 

Hi,

please consider how to charge the bootstrap capacitor. Maybe you need an extra low side mosfet (VS=Drain, GND=sorce, LO = gate) just to charge the bootstrap capacitor.

100p is way too low for a bootstrap capacitor.

Add the recommended capacitor at VDD as well as VCC (at least one is missing)

In any case:
Datasheet says:
"All voltage parameters are absolute voltages referenced to COM"
So COM is the reference for all voltages and should be connected to GND.

Klaus
 

Thanks a lot. I did what you said. my error was solved. but the mosfet doesn't drived and it is still always OFF.
my new circuit is:
2113.png
 

Hi,

Again:
lease consider how to charge the bootstrap capacitor. Maybe you need an extra low side mosfet (VS=Drain, GND=sorce, LO = gate) just to charge the bootstrap capacitor.
Click to expand...

Klaus
 

Hi,

It won't work as long as the bootstrap capacitor isn't charged.

Klaus
 

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