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raintalk 20th January 2006 06:18 PM

Anybody play with these yet?

Or should this post be in Chip Amps?

BTW - it does list a high PSRR

BWRX 20th January 2006 07:05 PM

It looks like it would be an interesting chip to work with (I don't like the TQFP package it comes in though).

It lists a high PSRR but that's only at 1kHz where that figure just so happens to be at its best (marketing strategy...). At 20kHz the PSRR is closer to -50dB instead of the -90dB at 1kHz. I also hate how everyone markets their stuff as 25/50W when that's at 10% THD+N...

It can be used without an output filter but it would radiate a lot of HF garbage, so it would be best to use a filter if you planned to make an amp based on this chip.

You can peruse spec sheets all day but that won't help you figure out how the thing will actually sound. If you're feeling adventurous take a stab at building one. That's what I'm doing, just with something else ;)

sagarverma 5th July 2006 07:04 AM

I have a couple of these with me.
Has anyone used this ic i.e implemented it as an amplifier before?
can someone design the pcb for this ic based on the application circuit in the datasheet pdf( .there is a evaluation kit also for this out here>>
the package that i have is THIN QFN, 56 lead.


electroconico 20th December 2010 07:52 PM

2 Attachment(s)
How good is the max9709?:confused::confused:

Im working on the pcb design.


sudheerfirst 21st December 2011 06:46 AM

hi sir
please tell me the availability of max 9709 in india

BhavaniSingh 17th May 2012 02:01 PM


Originally Posted by electroconico (
How good is the max9709?:confused::confused:

Im working on the pcb design.


Hi sir,
can u provide me the schematics for your design, and can u just tell me how is the MAX9709 working, is it reliable as i'm about to design an amplifier out of those, so please provide me the data.

Thank you

doctormord 7th August 2012 02:57 PM

4 Attachment(s)

i build myself a 9709 monostage in 1-layer-design. So far temperature is not a problem, but i havent tried a 100%-run on 22V.

Powered by 12V PSU the IC topside will be at ~42C after 10 minutes of 1kHz square wave input near clipping, so at 12V supply voltage, no additional heatsinking is required.

Strangely the IC is only pulling some 800mA from the PSU at this, so i gues impedance of the speaker is not as low as 4ohms.

Layout is working as is and it is considered to place a heatsink on the bottom side of the pcb.

Working params are:
SSM 200kHz +/-4
Mono bridged (1x50W)
22V max input
36dB gain
120C temp shutdown via /mute input
filterless output

Cheers doc

doctormord 8th August 2012 09:23 PM

2 Attachment(s)
There it is.

electroconico 9th August 2012 12:02 AM


It looks great!

necrofago 28th August 2012 11:57 PM

Doctormord do u mind share ur .brd archive? or the pdf whit the pcb rdy to print?

I want build this amp for my pc speakers.

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