TI TPA3100D2, Amazing Class D Amp

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Data sheet fig 27

This one configured as sub driver...same board
 

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I just asked Cristi of Connexelectronic if he would consider designing an amp based on the new TPA chips. He just replied that he would consider designing an amp, possibly with onboard smps which is his specialty. I've used several of Cristi's amps, they are very very well designed and he has many happy customers. I suggest anyone interested in these TPA chips head to the Class D Connexelectronic forum here to let him know there is interest for such an amp!
 
cervelorider (posts here) built me a tpa3100 amp (parts express board), I'm sure he'll build you one too.
Here is is very nice website.
http://www.fleawatt.blogspot.com/
But I think he's moving on to tpa3122 now.

I just hooked mine up this morning.

tpa3110amp_zps128cd9af.jpg


FLEAWATT : Fleawatt Cigar Box Amplifier

I'm using it with a revealing 110db jbl 2407 compression driver on a nice round mcm horn (54-580).

001_zps9b053815.jpg




Has anyone bridged the 3110 ?
Seems to me the lack of output filter (only ferites) goes a long way on improving the sound vs a 12 or 18db filter with their numerous parts.

Norman
 
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Norman,
Cervelorider makes nice stuff and is a great guy. I think the 3110 is designed for ferrite bead chokes if the speakers are very close to amp with short run of like a foot (like a boom box). I think their literature says to use a real wound inductor and capacitor and resistor network filter for long runs up an external speaker. Also, I think it is bridgable but not sure if the Sure board is set up to allow that. How does it sound with your CD and horn setup?
 
tpa3110 is already bridged. Tpa3116 and Tpa3118 are both the same chip, one with heatsink pad up allowing adding of heatsink above chip and other using pcb for heatsinking thus the lower power ratings. Thats why I said you already built tpa3116 since your dead bug chip was upside down with heat pad up.

tpa3130 is lower current version more suitable for 8 ohm loads.
 
I am using the Parts Express TPA3110. It is a terrific amp. And only $10(!!!!!!). It's pointless even trying to convince anyone how good it sounds because it's so cheap. However it is also an older chip like the 3100D2 and the 3122/3. The 3116/8 chips are the newest and the TI docs show improved channel separation and distortion, so I am really hoping Cristi gives them a go.
 
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TPA3116 pdf here:

http://www.ti.com/lit/ds/symlink/tpa3116d2.pdf

jpg shows different thermal resistances to heat sink pad. (from data sheet)

I had thought that the TPA3116 had higher output current but both the TPA3116 and the TPA3118 are rated for 7.5A while the TPA3130 is only 4.5A (bottom of page 6)

This is why I was spec'ing the more expensive 7.5 amp inductors at first. But when you pointed out thatook i=V/R we get 24 volts/8 ohms = 3 amps. For 4 ohm speakers you need more or for peak transients. But transients are short and inductor should be able to handle it. The inductors are the single most expensive part (besides IC and PCB) if you go with 7.5 amp units ($1/ea) vs $0.63/ea for 3 amp ones. Are you recommending the bigger ones now? That's what I have in the 3118 foam core build.
 
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Remember that even though the smaller inductors will handle the current, they will be at a lower inductance during that time.

This will change the filtering characteristics and the loading "isolation" for the IC.

I try to design with inductors that do not change more than 10% of value for max current.

Some data sheets give the inductance vs current graphs...these are the ones to look at because you know what they are doing.

IMHO, of course.
 
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I am going to see if I can pull up a spec sheet for the inductors I got. I doubt the cheap one has it, but the bigger one is a Bournes - reputable company probably has it. I never even knew about how the inductance can change with current. Thanks for pointing that out. So the 3 amp units you spec'd from Digikey have the proper behavior with current?
 
Hello Folks,

I am using the Murata 12RS333C for my TPA3100D2PHPR design. They are PTH types. I could not find the Toko ind's that were used by TI in the eval brd. As far as listening experience goes, they seem to be just fine. For my last build, Digi-key/Mouser did not have the (12RS333C) so I sub'd the 12LRS333C. I can not hear any diff. I have yet to actually do measurements of this amp.
Would like to know:
1) If you can share what exact inductor MFG PNs you are using?
2) What are your measurements and what is the setup? In my setup I would use an Amber 3501, since it has the balanced input option. I have measured the pre-amp in my design and it came in at ~0.03%@1kHz, just as Maxim spec'd for the part, so having it in the test path with the TPA3100D2 would be insignificant, in my mind.
I am considering designing a TPA3116/18 as well, since I like its AM avoidance & common footprint feature.To bad the 3116/18 were not avail when I did the 3110D2 dsn or I would have used them instead. Sonically, I do not think that there would be much diff. between the two, do not know for sure, until I try.

Cheers, keep up the great thread discussions regrading these great amps.
It is funny that I have the amp hooked up to a lab supply, so I can monitor the power/current, play with the V, etc. I can crank it and the I meter hardly moves at all. The LCD back light draws more juice :)
Rick
 
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