problem with IR2113

[7ormore]

I'm having a bit of trouble with my class-d the problem seems to be with the chip IR2113 the low output is good but the high output is wrong. Hopefully if the image i have loads then you will seen my design and possible errors, i believe i included everything


any help would be great

Brian

[Eva]

There is no image attached.

How are you charging the Vbs (bootstrap) capacitor?

[7ormore]

I'm using a .1uF cap between Vs and Vb. I'm a new member so i don't know if they'll let me put up an attachment, i have been trying tho.

Thanks

[luka]

use something like
http://s123.photobucket.com

[7ormore]

Well i hope this works. This is a very basic design i'm just trying to get the outputs of the IR2113 to be square waves. Any advise would be great, I havn't set up the output filter yet.




http://i607.photobucket.com/albums/t...d/class-d3.jpg

[7ormore]

http://i607.photobucket.com/albums/t...and/brian1.jpg


Maybe easier to look at it this way. We spent most of the day trying to think of what we are doing wrong with this circuit and why are IR2113 isn't working, we've tryed a few different chips to see if one was blown. Anyway if anyone has any ideas please let me know. also i forgot to label one of the chips but its IR2113.

Thanks
Brian

[Pafi]

7ormore!

What do you mean it "isn't working"? What do you expect from this circuit?

The schematics are not identical, on brian1.jpg the low side MOSFET gets a -25 V source voltage, wich is wrong.

If you want this to be an amplifier (or any useful circuit), then the schematics are basically wrong. But IR2113 should work in class-d3.jpg circuit (more or less).

[Eva]

All the circuits seem inadequate.

An op-amp or a comparator is not suitable as a means to produce complimentary HIN and LIN signals, consider delays. Use logic gates instead.

There is no level shifting of the drive signal.

Etc...

[7ormore]

Originally posted by Pafi
7ormore!

What do you mean it "isn't working"? What do you expect from this circuit?

The schematics are not identical, on brian1.jpg the low side MOSFET gets a -25 V source voltage, wich is wrong.

If you want this to be an amplifier (or any useful circuit), then the schematics are basically wrong. But IR2113 should work in class-d3.jpg circuit (more or less).

Sorry i wasn't sure how to diagram the voltage source. This is all being done on breadboard. the power mosfets are being driven from a DC generator while the chips are being powered by the cadet board.

Originally posted by Eva
All the circuits seem inadequate.

An op-amp or a comparator is not suitable as a means to produce complimentary HIN and LIN signals, consider delays. Use logic gates instead.

There is no level shifting of the drive signal.

Etc...

To clarify you mean i shouldn't use LM311 to compare my inputs to get a digital output? The other op-amp is LT1056 which i am using to invert the signal. I can see how these would cause gate delays. I could easily replace LT1056 with an NOT gate but i'm unsure what i would use to replace LM311

Thank you for the help as u can tell i'm a newbie, any help is more than welcome. Also if you want any pictures of anything that I am not making clear please let me know.

[Pafi]

This is all being done on breadboard. the power mosfets are being driven from a DC generator while the chips are being powered by the cadet board.

This doesn't tell anyting. OK, by the cadet board, but how? COM (and VSS) of the IR2113 should be connected directly to the source of the lower MOSFET!

I repeat: What do you expect from this circuit? What is this supposed to be? It's usable for testing the functionality of the IR chip, but nothing else.

Try to think it over what signal do you want on the load, and for that what is the appropriate switching topology (yours is good for nothing), and for that what are the neccessary gate-signals!