Hi,
Have you evaluated this TPA3116 solution before ?
The TPA chip and inductors are heat when operating or under the high power output. Therefore, my design is keeping in use the big inductors and TH parts. Avoided and minimized the board temperature transfer direct to SMD chip caps affect the filter Coefficient.
Nice board ! AFAIK the best till now. I hope YJ engineers will copy that one.
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Yeah. Not too difficult with with 58x23mm. Now imagine you used 3312 (or 3412) smd case size ferrite beads instead of inductor/capacitor output filter and optimized the components a bit more on the input side of the chip and you'd have room some (small) bulk caps as well. In principle these could be moved to the corners on the output side if they're too large to fit anywhere else but I'd try to avoid that and have them as close to the chip as possible.
Saturnus, is size the most important parameter or is it sound quality with your design ?
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The capacitors on the amp board are for decoupling. These should be as close to the chip as possible. The principal requirements are very high ripple current handling capacity and very low ESR. It should not be their role to be bulk caps to ensure that the power supply can supply the requested current, that is the role of the power supply. If you indiscriminately add capacitance after a switch mode psu you will remove it's capability to react to current changes, and so you need to add a lot more capacitance to make up for that. So large bulk capacitors on the amp board is definitely not a good idea, that is reserved for the power supply instead but that requires that you make a lay-out with as wide Vcc routings as possible.
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I think the two are related. The tighter you can squeeze it while not sacrificing component quality or best practice layout in the process the better the sound.
The RC snubber is supposed to be as close to the output terminals as possible. It doesn't make a difference which side of the output terminals it's connected to.
Also it doesn't look like vias to me. More like not completelt finished routing.
Also it doesn't look like vias to me. More like not completelt finished routing.
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I agree with you. However, having conducting research for a living for over 30 years as a scientist. The theory has to be tested and the results analysed and gauged. In my line of work, we conduct experiments everyday changing different parameters hoping to improve the end results. Some change were made based on speculations. Some changes are made based on theory or new findings from other people. I can tell you that not all changes that are "suppose" to work deliver results.
For sure , best practice would do no harm. It is essential but may not be sufficient to achieve good results that we expect.
Regards,
Not really in my opinion as it would imply a difference between the two. I see reduction of size as much as possible as a means to achieve even better sound quality, not a compromise.
They are vias...small sacrifice for quick fit.
Some rules are bent when making things compact.
IMO the bottom copper ground plane is also compromised by the two inductors on the bottom.
FWIW these inductors that I use are good for 3A loads, ( 24V 8R or 18V 6R ) so I do not use them for "high power".
🙂
http://www.diyaudio.com/forums/clubs-events/212618-greater-toronto-area-diy-meetup-23.html
pix in post 230
The schematic is from the data sheet...only change is 470uF bulk caps and input cap value...and some options on the sync connections.
I think the via for the inductor allows placement of one set on one side and other side for second set.
The speaker terminals are on the left side of filter because right side is ground terminals of filter resistors and caps.
The circuit is probably identical to TI recommend one just topology wrapped on end and both sides for compactness.
I think that is how Dug laid it out - at least when I look at the circuit as drawn.
The speaker terminals are on the left side of filter because right side is ground terminals of filter resistors and caps.
The circuit is probably identical to TI recommend one just topology wrapped on end and both sides for compactness.
I think that is how Dug laid it out - at least when I look at the circuit as drawn.
Your reply reflects that size is more important to you than quality as there is no absolute correlation between size and quality. Larger boards with crucial parts close to the chip need not be worse than ultra compact boards with thin traces and the same distance between parts and chip.
If someone could make a 4 channel amp that has same footprint as a miniDSP 2x4 board and could stack on it with standoffs that would be attractive. Stock miniDSP class D amp is only 10 watts/ch. I am buying two separate boards now and they won't be stackable. Or maybe a 2 channel PBTL (stereo) that uses 2 amps for 100 w/ch at 2 ohms?
Size is dependent upon the choice and availability of components in said design. The mechanics of the packaging also come into play.
In my design the components that take up to most area are the coupling caps, if you decide to use film PP types, inductors, heatsink for 3116.
See attached.