First Circuit - TDA1517P - Page 1
Forum section: electronics / beginners

author: vidarr
author_rank: Frequent Contributor
timestamp: October 17, 2018, 01:51:21 am
content: Finally did it and built this amp circuit. It is my first "real" circuit from scratch (I have ESP32s and other dev boards, I connect sensors and program, etc). I never really built anything. Everything was recycled from about 10 different electronic devices I picked out of the trash over the past year. For the past month or two, I de-soldered a lot of pieces and learned what they all are and looked up datasheets and read, etc. The amp was from a sound card. Finding this was what decided what I was going to build - I needed some "seed". This circuit was built from the datasheet for the amp IC -- TDA1517P.I want to take this to another level now. I have piles of resisters, capacitors, transistors, diodes, etc. I would like to increase the power of this little amp just a little bit. Not a lot at all. Just a little boost. I have sets of 2, 4, 6, 8 ohm speakers. This amp is for 4 ohm speakers. The speakers now are 4 ohm, but I know they can handle more power. Would be nice to get a little more out of it. I watched tutorials about building an amp out of transistors instead of a more complete IC like I used, but I never found a way to build on to an IC like this. How to add to it?Thank you for any ideas or help!

author: Wimberleytech
author_rank: Super Contributor
timestamp: October 17, 2018, 02:10:20 am
content: Congrats on your first circuit.The output power is specified at Vp=14.4 volts. How are you powering the circuit?

author: vidarr
author_rank: Frequent Contributor
timestamp: October 17, 2018, 11:41:18 am
content: I have two power supplies. One is the 12v in the picture (just a typical, decent quality, alixpress 12v). The other is a power supply ranged from -12v to +12v, with also 3.3v, 5v, 0, -5v, GND. I have not tried using this second psu yet. I am not sure exactly how to do it. Maybe -12v and +3.3v???edit: The datasheet says 6v min to 18v max.Also, is says reverse polarity 6v. Does that mean I cannot use -12v?

author: Wimberleytech
author_rank: Super Contributor
timestamp: October 17, 2018, 02:25:57 pm
content: Quote from: vidarr on October 17, 2018, 11:41:18 amUse the 12V supply.The chip is protected from a reverse-polarity fault up to 6V. Don't worry about that spec, and don't reverse the polarity of the supplies.Connect ground of the supply to ground of your circuit (pins 2 and 5), and +12V to Vp (pin 7).

author: vidarr
author_rank: Frequent Contributor
timestamp: October 17, 2018, 02:49:25 pm
content: Yeah, that is how I did it and it seemed OK. I just want a little more power. Do you think it is the 12v not enough?I want it to be just a bit louder, then I will solder it together and put it in a box.

author: Wimberleytech
author_rank: Super Contributor
timestamp: October 17, 2018, 03:01:22 pm
content: Quote from: vidarr on October 17, 2018, 02:49:25 pmTake the power supply up to 18V (the max value). If you don't have an 18V supply, for now, just put a couple of batteries in series with your supply and see if that is good enough for you.

author: mariush
author_rank: Super Contributor
timestamp: October 17, 2018, 04:11:59 pm
content: Not much you can do about it.That particular chip can only do 2 x 6 watts but only if the voltage is high enough (maximum 18v, typical 14.4v) so you should aim to get the voltage as close as possible to 18v.With 12v, the output power will be more like around 3.5-4w per channel.If you have two identical chips or you can source a second one, then you could configure each chip as a mono amplifier (bridge mode) so you get a single maximum 12w amplifier.The datasheet for TDA1517 doesn't have an example circuit, but the TDA1519 has one (I'm attaching it here). Chips should have the same pinout but double check it anyway.

author: rsjsouza
author_rank: Super Contributor
timestamp: October 17, 2018, 04:33:25 pm
content: Congratulations on your adventure!A few comments:Quote from: vidarr on October 17, 2018, 01:51:21 amHow are you exactly planning to increase the power? Don't forget that, if you try to push 6W out of this IC, you will have 10% distortion.Reducing the speaker impedance tends to yield a bit more power, but unfortunately the datasheet does not show any data for an impedance of 2\$\Omega\$.I personally wouldn't use the absolute maximum voltage of 18V - a margin of error is always better. If you still want to do this (and use the 2\$\Omega\$ speakers), be sure to solder pins 10~18 to a very large PCB copper area (maybe even a dual layer PCB) in order to dissipate the heat of the IC.Quote from: vidarr on October 17, 2018, 01:51:21 amI am not sure if I understand this sentence. Do you mean adding power transistors to the output of this amplifier? Although possible, I would try first to assemble the circuit you have and then design a power stage later.

author: rsjsouza
author_rank: Super Contributor
timestamp: October 17, 2018, 04:39:25 pm
content: Quote from: mariush on October 17, 2018, 04:11:59 pmInteresting; I use theTPA1517(from TI) but was unaware to the fact it says it is TDA1517 compatible. Its datasheet has much better characterization curves, as well as adevelopment boardwith the circuit diagram, board design, etc.

author: vidarr
author_rank: Frequent Contributor
timestamp: October 17, 2018, 11:50:58 pm
content: Thank you everyone! Read everything you guys wrote.I found a 16v psu from some other device and a switching psu that goes from 12-22v. I am going to use the 16v.The idea of using two of these chips together is a really good idea. Thanks for that."Do you mean adding power transistors to the output of this amplifier? Although possible, I would try first to assemble the circuit you have and then design a power stage later."Yes, that is what I meant. I am going to try this other psu first. I am also going to plug my 2ohm speakers into the circuit and see what that is like. I live in a city a block from the ocean; I just want to be able to hear music and news on my balcony/porch. If I cannot do that, oh well. I put it in the kitchen or something. It wasn't a necessary amp, just something cool to have around because I made it.It would really be good to know how to add power transistors to this. Even if I do not do it for the final, I still want to know. Maybe I do another time. Anything good for a schematic, or video tutorial, anything like this would be great. I cannot find this.I have some extremely rare Brazilian wood from the Amazon rain forest that was cut about 200 years ago by the Portuguese conquerors (it is illegal to cut down now). I have a lot of this wood for free and keep finding it weekly -- that is whole other story if you want to hear it. Going to use that wood for part of the box with an aluminum heatsink on the amp chip. Real simple box... like a toggle switch, volume knob and a light.Thanks!

author: Audioguru
author_rank: Super Contributor
timestamp: October 18, 2018, 01:29:06 am
content: The NXP datasheet is missing many details so it is almost useless.You have the IC that has a package (P) with poor cooling. The cooling is much worse on your Mickey Mouse solderless breadboard.The maximum allowed chip temperature is 150 degrees C. The ambient temperature might be 30 degrees C. 1W of electrical heating produces 15 degrees C.Then the chip will be at its maximum allowed temperature when the electrical heating is (150 - 30=) 60 degrees C. 60 degrees/15 degrees per watt= 4W. The TI graph of heating vs output power shows a maximum heating of 2.3Wper channelfor a total maximum heating of 4.6W when the supply is 12V. Then it overheats.You know what? The maximum idle current is 80mA which produces heating that is almost 1W. Then the maximum power before a meltdown is about 1.5W per channel. The larger packages have a cooling "fin" that can be bolted to a heatsink for much better cooling then the output power can be 5W per channel.

author: alsetalokin4017
author_rank: Super Contributor
timestamp: October 18, 2018, 02:10:28 am
content: Put the speakers into some kind of enclosures. Even little cardboard boxes will improve the sound and the volume quite a bit. Peanut cans, chow mein noodle cans... anything that will give the cones a little back pressure and some resonant cavity. You'll be amazed.

author: vidarr
author_rank: Frequent Contributor
timestamp: October 18, 2018, 11:16:41 am
content: Quote from: Audioguru on October 18, 2018, 01:29:06 amYeah, all it did was show the schematic on a sample circuit, with some power values to make it work and stuff about the chip. But, it is all I could find.Quote from: Audioguru on October 18, 2018, 01:29:06 amFirst of all, I do not have the "Mickey Mouse" solderless breadboard. I have the "Phantom Blot" solderless breadboard (see pic). Mickey Mouse is for kids.Quote from: Audioguru on October 18, 2018, 01:29:06 amMy computer is liquid cooled. I built it all by myself (see pic). That may be a bit much for a chip like this -- as overwhelming as its power is. But, I have a lot of heat sink options (see pics). I think the laptop, cpu/gpu fan could be pretty cool -- especially if I do what mariush suggested and run two chips. That would be really cool.Quote from: Audioguru on October 18, 2018, 01:29:06 amNo, I do not. What?Quote from: Audioguru on October 18, 2018, 01:29:06 amYes, I saw that. Unfortunately, when I was picking through the garbage, I only saw this one. It is very hot where I live too. Ambient temperature is about 32C right now (not in the sun). I should be fine with the cooling options in the pic. I would hate to have to throw this chip away -- again. LOL.Speaking of heat and boards... I am going surfing. It is an awesome day today. Do you know girls wear g-strings for bikinis here. It is crazy. Naked butts everywhere.

author: vidarr
author_rank: Frequent Contributor
timestamp: October 18, 2018, 11:23:21 am
content: Quote from: alsetalokin4017 on October 18, 2018, 02:10:28 amYeah, I have some ideas but I haven't built anything complete yet, still just partial builds using the wood I mentioned. Trying to find the right design. Fiddled around with transmission lines for a little while. Kind of interesting.The 2ohm speakers have an enclosure already. They suck, but for quick testing it is ok.Thanks Guys! Time to surf.edit: I researched some power transistor circuits last night. Is it right that I would need to have a separate power supply to add this to the circuit? If so, wouldn't it be better to build a separate power transistor amp that the TDA1517 chip circuit "plugs into"? Or would I provide two power supply inputs into a single circuit? I am starting to get confused again (not incredibly difficult with this stuff).Thank you everyone! You have been incredibly helpful. I think you guys will be impressed with the final product.