Fez, another great video mate, thanks for the effort you put into these! You might find that chip is a PAM8403. I have found allot of these boards use the wrong value caps that tends to screw up the performance.
Yes it is the PAM8403. I have also a few of such class D modules laying around which I have used to test some audio circuits in an audible way. I have found that thay cause a lot of EMI. So I made some audio modules using the class AB TDA2822 in BTL configuration by myself. I also have some commercial class AB modules using the LM386 but these modules are sensitive to grounding issues on breadbords. My BTL modules are much less sensitive to this due to its BTL configuration and they operate down to 2 V power supply voltage.
Regarding your comment on t=2m12s, comparing a channel 2 with channel 1 (=ref) is also a good idea because of the input channels themselves! If you use AC coupled channels, the phase starts to rotate much further in the frequency then you expect, and that also goes for the other end. So a bandwidth of 40 kHz will not give you 0 degrees phase up to 40 khz. Therefore, comparing 2 over 1 also divides away those issues, next to the other things you mentioned.
It is impressive to see that these low cost class D amplifiers run at such a high PWM frequency. They are clearly designed to run in filter-less configurations. But their EMC should be not really good. I live in Germany and I think, these amplifiers are not allowed to run in filter-less configuration, as they cause 1.5 MHz radiated emissions with considerable magnitude.
I would be happier if you place the filter components into a real life PCB with calculated trace parameters (EMI etc). Most electronicians dismiss this. Best regards&thaks for your effort.
I will be honest, I thought it was a PAM8403, but that component has a switching frequency of ~250KHz according to its datasheet; the IC I have is running at 760KHz...
Hi Master Fez.. I have a confession.. I love your videos and have quite a few saved on a playlist for when I get around to clearing my mind and spending som quality time learning from you.. the "problem" is finding the time and the "cognitive freshness" to do so.. your videos demands a bit more thought process than videos with kittens or people doing stupid things.. what I'm saying is that you probably have around 100 future views from future me that just is not in your RUclips view metrics thingy and I'm probably not the only one that has videos stored like that.. I hope to get around to knock some of my electronics playlist down and thus generating some of the views your videos deserves.. cheers
Hello Tacit! I never intended to make easy to digest videos but I try not to make things to complicated either... Even if I really like cats, I don't own one... Well I'm always is search of new and interesting topics - maybe you can share some of your interests.
@@FesZElectronics If you can, please, make video about full design and calculations of RF amplifier (I mean calculating input impedance of rf amplifier and input circuit design for amp)
Hi, I have been building speakers for quite a while now. Lately I wanted to design my own Class D amp. One thing I want to mention is, that the impedance changes heavily over the f range. And a tweeter almost never has its nominal Z at around 20khz. More like 20 to 40 ohms. So when the filter kicks in at around 15khz, why should you design the filter for 2, 4 or 8 Ohms?. As the real load isn't the nominal value. And the Q factor is something completely different than simulated. Or am I wrong?
Excellent presentation and very thorough walk-through of the measurement techniques. Thank you for taking the time to make this series of videos.
Fez,
another great video mate, thanks for the effort you put into these!
You might find that chip is a PAM8403.
I have found allot of these boards use the wrong value caps that tends to screw up the performance.
Yes it is the PAM8403. I have also a few of such class D modules laying around which I have used to test some audio circuits in an audible way. I have found that thay cause a lot of EMI. So I made some audio modules using the class AB TDA2822 in BTL configuration by myself. I also have some commercial class AB modules using the LM386 but these modules are sensitive to grounding issues on breadbords. My BTL modules are much less sensitive to this due to its BTL configuration and they operate down to 2 V power supply voltage.
Great videos! Greetings from Brazil!
Regarding your comment on t=2m12s, comparing a channel 2 with channel 1 (=ref) is also a good idea because of the input channels themselves! If you use AC coupled channels, the phase starts to rotate much further in the frequency then you expect, and that also goes for the other end. So a bandwidth of 40 kHz will not give you 0 degrees phase up to 40 khz. Therefore, comparing 2 over 1 also divides away those issues, next to the other things you mentioned.
It is impressive to see that these low cost class D amplifiers run at such a high PWM frequency. They are clearly designed to run in filter-less configurations. But their EMC should be not really good. I live in Germany and I think, these amplifiers are not allowed to run in filter-less configuration, as they cause 1.5 MHz radiated emissions with considerable magnitude.
I would be happier if you place the filter components into a real life PCB with calculated trace parameters (EMI etc). Most electronicians dismiss this. Best regards&thaks for your effort.
Can a Class D Amplifier be used for HF Amplification, if the components are chosen right ? Which amplifier ist the best suited for High power HF?
Thanks! Will you cover class AB as well? Or perhaps other classes?
I think the next class I will cover is again class D but when its used to amplify RF signals.
@@FesZElectronics awesome! Its great that you are targetting RF.
Nice experiment. 10:27 I think that chip is PAM8403.
I will be honest, I thought it was a PAM8403, but that component has a switching frequency of ~250KHz according to its datasheet; the IC I have is running at 760KHz...
get variable components. to adjust precisely. Like variable inductors.
Hi Master Fez.. I have a confession.. I love your videos and have quite a few saved on a playlist for when I get around to clearing my mind and spending som quality time learning from you.. the "problem" is finding the time and the "cognitive freshness" to do so.. your videos demands a bit more thought process than videos with kittens or people doing stupid things.. what I'm saying is that you probably have around 100 future views from future me that just is not in your RUclips view metrics thingy and I'm probably not the only one that has videos stored like that.. I hope to get around to knock some of my electronics playlist down and thus generating some of the views your videos deserves.. cheers
Hello Tacit! I never intended to make easy to digest videos but I try not to make things to complicated either... Even if I really like cats, I don't own one... Well I'm always is search of new and interesting topics - maybe you can share some of your interests.
@@FesZElectronics If you can, please, make video about full design and calculations of RF amplifier (I mean calculating input impedance of rf amplifier and input circuit design for amp)
Hi, I have been building speakers for quite a while now. Lately I wanted to design my own Class D amp. One thing I want to mention is, that the impedance changes heavily over the f range. And a tweeter almost never has its nominal Z at around 20khz. More like 20 to 40 ohms. So when the filter kicks in at around 15khz, why should you design the filter for 2, 4 or 8 Ohms?. As the real load isn't the nominal value. And the Q factor is something completely different than simulated. Or am I wrong?
That's why class d amplifiers are mainly use for powered speakers which is one amp and one speaker adjusted dedicately to each other.
👍
Please do Ltspice simulation tutorial.
I do have quite an extensive set of tutorials already. Or is there a specific subject you would be interested in?
@@FesZElectronics please do LTspice on buck and boost closed loop control design
How to improve class D amplifier sound better, should remove the filter?