IR21844 based amp?

[mbates14]

any self-oscillating/UcD amplifier schematics around that use the IR21844?

I have a few of these guys laying around and need to work up a small amplifier module to replace an output module of a subwoofer.

any ideas? Most of the ones I find on the web are based around the IR2010S or 2011. I have the 21844.

 

[MOER]

IRS21844

The chip is too slow for full range class D

Steve Mantz
Zed Audio

 

[Dimonis]

The chip is too slow for full range class D

Not exactly slow , but having a large DT it produces large THD . Something about 0.1%. It will do for a subwoofer.

 

[Dimonis]

any self-oscillating/UcD amplifier schematics around that use the IR21844?

I have a few of these guys laying around and need to work up a small amplifier module to replace an output module of a subwoofer.

any ideas?

I made several amps based on IRS2184 chip. Look here. ?????? ??????? ?????????? - ????????? ???????? ?????? D - ????? ?? ????????????????. This amp has a combined feedback. It works well only as a sub amp. I also made an amp with second order loop UcD feedback and it sounds well enough in full range mode. I'll post it later here , when I get home to my PC.

 

[mbates14]

Well Perhaps I wasnt clear. I forgot to mention that I am not building a full-range unit. I am building a subwoofer amplifier, so that chip should be ok.

 

[Dimonis]

Catch

 

[Dimonis]

Some foto & info more :

 

[Dimonis]

Here is the one with the discrete modulator , with low&high pass filters on board.

 

[mbates14]

Thats basically what I needed.

I am building this circuit to replace the S64AMI module in a crappy JBL Subwoofer.

 

[Dimonis]

To post #8

 

[mbates14]

Na, no discrete stuff with me. id rather use an op-amp

 

[Dimonis]

Hi mbates14 ,
what output power do you need ? Load resistance ?

 

[mbates14]

load resistance is 4 ohms. output power maybe 200w or so.

 

[Dimonis]

You have a ready power supply in your sub ? What voltage?

Your sub is PB10 ?

 

[mbates14]

Its the PB12 I think... maybe the pb10. I am going to use the existing plate and preamp/power circuitry and tie my poweramp into it.

 

[Dimonis]

PB10 has +/- 47V power supply . It's suitable for 200W 4Ohm. You can use also the 110uH inductor. What mosfets are you going to use in the output stage?

http://www.acousticpsychos.com/Files/JBL/JBL-PB10-sub-sm.pdf

 

[mbates14]

probably what i have on hand. IRF3415 or IRFP3415. I Keep those around as I do alot of repairs.

 

[Dimonis]

Don't think a good idea . They are too "heavy" , too big Miller charge .

 

[mbates14]

How so? I used them in just about every D amplifier I had repaired and never had any issues.

 

[Dimonis]

in just about every D amplifier I had repaired and never had any issues.

What oscillating frequence ? Yes , they shall work , but the efficiency will be low . If you have large heatsinks - they'll do. But require a large DT.

I prefer little heatsinks 😉 as in my foto's above .