IR2113 blowing ! help needed... - Page 3

Baldin · 10th January 2007, 05:40 PM

Hi alexclaire

Very interesting project. Nice PCB

I think fredos is right about the 1N4148 for gate diodes. In my circuits these have been no problem.

Is the amplifier loaded when you drive it to clipping?

Is there no problem in driving it quite hard (but nor going into clipping) in a 8 ohm load?

Are the mosfets getting hot at any condition.
In idle, with no load they should not get more than luke warm, otherwise, I think you have shootthrough.

I have experimented a bit with IR2110, and I had to add additional dead time with some IRF640 to avoid shoot through (which I think is faster than the types you are using).

Are you sure it is not the fets that are giving in first, and dragging the driver down in the fall?

I'm not too sure about the fets you are using, have you tried some cheap ones like IRF640, IRF540 or the like?

I would maybe try these out, with a lower Vcc/Vss just to make sure things do work, before going to +-80V whoch is quite a lot (~400 W @ 8 ohm)

And as fredos suggests, some decoupling near the fets would be good (cant see whether that is already the case in your design).

Have you tried putting a scope on the mos output?

If it's not self oscillating, I think you should maybe try to disconnect the feedback until everything else works.

Looking forward to hearing more about this project

alexclaire · 10th January 2007, 05:59 PM

Hi,
The signal before the output coil is very clean at idle: 50% duty cycle, +80v -80V with no ringing at all...
Fets and output coil are cold at idle.
Coil remains cold at 350WRMS@8ohms but fets become a little warm (temp rise ~20°C).

I m gonna add 470nF capacitor between +Vcc and -Vcc as close as possible to the fets.

Any other advice ?

Thanks for the support ;-)

alexclaire · 10th January 2007, 06:01 PM

Hi Baldin,
yes I'm not sure if the driver blow before fets...

I 'm gonna make all the changes i said and see...

alexclaire · 10th January 2007, 10:00 PM

here are some pics of the amp running...
1 test bench during measure

alexclaire · 10th January 2007, 10:03 PM

pre filter signal at idle...
1/10 voltage division so ~160Vpp...
80ns rise time and fall time

alexclaire · 10th January 2007, 10:06 PM

post filter signal at idle...
a bit much ripple isn't it ?

alexclaire · 10th January 2007, 10:07 PM

duty cycle variation...

luka · 10th January 2007, 10:08 PM

I that much with load connected?

alexclaire · 10th January 2007, 10:09 PM

65Vpp 1kHz (9.4 ohms load)...

alexclaire · 10th January 2007, 10:11 PM

over 35Vp signal is overshooting...(whatever frequency) why ?
clipping occurs at 72Vp...

10th January 2007, 05:40 PM	#21
Baldin diyAudio Member Join Date: Jan 2005 Location: Copenhagen	Hi alexclaire Very interesting project. Nice PCB I think fredos is right about the 1N4148 for gate diodes. In my circuits these have been no problem. Is the amplifier loaded when you drive it to clipping? Is there no problem in driving it quite hard (but nor going into clipping) in a 8 ohm load? Are the mosfets getting hot at any condition. In idle, with no load they should not get more than luke warm, otherwise, I think you have shootthrough. I have experimented a bit with IR2110, and I had to add additional dead time with some IRF640 to avoid shoot through (which I think is faster than the types you are using). Are you sure it is not the fets that are giving in first, and dragging the driver down in the fall? I'm not too sure about the fets you are using, have you tried some cheap ones like IRF640, IRF540 or the like? I would maybe try these out, with a lower Vcc/Vss just to make sure things do work, before going to +-80V whoch is quite a lot (~400 W @ 8 ohm) And as fredos suggests, some decoupling near the fets would be good (cant see whether that is already the case in your design). Have you tried putting a scope on the mos output? If it's not self oscillating, I think you should maybe try to disconnect the feedback until everything else works. Looking forward to hearing more about this project __________________ Visit www.sensibleaudio.dk or read latest news on Baldin's Blog

10th January 2007, 05:59 PM	#22
alexclaire diyAudio Member Join Date: May 2005 Location: Avesnes/Helpe	class d amp Hi, The signal before the output coil is very clean at idle: 50% duty cycle, +80v -80V with no ringing at all... Fets and output coil are cold at idle. Coil remains cold at 350WRMS@8ohms but fets become a little warm (temp rise ~20°C). I m gonna add 470nF capacitor between +Vcc and -Vcc as close as possible to the fets. Any other advice ? Thanks for the support ;-)

10th January 2007, 10:08 PM	#28
luka diyAudio Member Join Date: Sep 2005 Location: in Slovenia :)	I that much with load connected? __________________ home page @ http://www.classdaudio.co.cc @ 24/7 all year long I FEEL SLOVENIA

Thread Tools	Search this Thread
Show Printable Version Email this Page	Search this Thread: Advanced Search

Similar Threads
Thread	Thread Starter	Forum	Replies	Last Post
problem with IR2113	7ormore	Class D	32	6th May 2009 03:20 PM
How to use IR2113	StevenTam	Class D	5	16th September 2008 03:56 PM


	Please consider donating to help us continue to serve you. Ads on/off / Custom Title / More PMs / More album space / Advanced printing & mass image saving

10th January 2007, 06:01 PM	#23
alexclaire diyAudio Member Join Date: May 2005 Location: Avesnes/Helpe	Hi Baldin, yes I'm not sure if the driver blow before fets... I 'm gonna make all the changes i said and see...

Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)

New To Site?	Need Help?
Register to Participate Search Privacy Statement Contact Us	Frequently Asked Questions Did you forget your password? Mark Forums Read