Distorsions in class D

[Workhorse]

Hi Choco,

What happened to your project?

regards,
K a n w a r

[ChocoHolic]

Hi Kanwar,
I opened my thread about my babysteps of my Class D Rookie... Well... had some drawback, because I fried my hard disc by a short circuit from my 2kVA PSU ==> USB scope ==> internal GND of notebook ==> hard disc ==> enclosure of hard disc ==> screw at hard disc cover ==> metal rack on which the notebook was standing (while I thought it would be floating well isolated... ) ==> PSU...
OK, only the hard disc was fried, all the rest of the notebook seems to fine. ..running again.

I went on and since about one month I am strugling with the weaknesses of the IRS20954S. It is oversensitive vs noise. I managed to get it working up to something about 40A..50A even with the noise at hard switching conditions. But I wanted to have proper operation up to 60A..70A (did not work out so far) and then set the current limit to 55A. Furtheron the IC can be killed by the MosFets reverse capacity. I was able to cure this by an external driver.... STOP !!! Too many work arounds and still no satisfying behaviour. I think now I know why IR does promote this IC just for 200W, while the voltage rating and 1A driver capability in the data sheet would indicate to use it also in higher power amps...

I am right now changing my concept to:
Hysteresis resonator + level shift towards neg rail + IR2113 halfbridge driver + discrete shut down circuit
Will post the new schematic soon in my babystep thread.

Bye
Markus

[Workhorse]

Originally posted by ChocoHolic
Hi Kanwar,
I am right now changing my concept to:
Hysteresis resonator + level shift towards neg rail + IR2113 halfbridge driver + discrete shut down circuit
Will post the new schematic soon in my babystep thread.

Bye
Markus

Hi Markus,

Thats good,
IR2110/2113 is wise solution and much robust as its the industrial workhorse of many offline smps...as well as Class-D amps


waiting to see your schematic,

Cheers,
K a n w a r