Anybody explain why I can't get excatly the same parameters like from SigmaDSP, I have made functions for calcultating coeficients and its very similar but as you can see its diferent a bit. Here is my code https://pastebin.com/izF4Rp3u and screenshoot from SigmaDSP and Putty values from my C program . Dsp is ADAU1462, filter is of type 2nd order general filter, clickless (HW slew). Might be that I need to add slew value to the formula? What I have missing do you have idea? Thanks!
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In relation to post 82, first ganFet prototype, UVP, OVP, cycle by cycle OCP, temp, DC, LPM, autostart, standabay... etc a lot of protections and features. Working on Hypex SMPS400-180 x 2 mono. CNC machined heatsink 105x76 at a bottom. No opamps... etc
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Fronted for DDPD almost finished, remain J.Didden on the left bottom of the pcb and rest of some routing. Specialy made J.D. 5V pre-regulator https://www.diyaudio.com/community/threads/super-regulator.247281/post-7244812 to supply ten small 3.3V and 1.2V regulators on this pcb. Master clock CCHD-575 with CY2308SXI-2 zero delay divider & buffer
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DDPD priject is now open source, more info https://www.diyaudio.com/community/threads/direct-digital-power-dac-ddpd.395974/
Jet another DSC with discrete i/v, mfb, tone control and se to diff, will combine them with ucd180 and digital frontend based on ct7302pl. This one is mono, single ended. Pcb 75x50mm
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Brother & sister == SMPS400A180 + DDPD
Mono pair, I want dual mono, so need another ddpd+smps. Box layout will be mono left, than metal partition as rfi shield, in the center DDPD frontend, than again metal partition, than mono right. Box will be CCA ~300 x ~200 mm
Mono pair, I want dual mono, so need another ddpd+smps. Box layout will be mono left, than metal partition as rfi shield, in the center DDPD frontend, than again metal partition, than mono right. Box will be CCA ~300 x ~200 mm
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Pcb finished, waiting heatsink from manufacture. The next step is soldering frontend which contain two ct7302, ct7601 usb, dsp, fm radio, bluetooth, 4 optical inputs, two i2s inputs, after that need to finish atenuator+dummy load+diy aux0025 filter and only than I will be ready to connct things together to power supply and test it, a lot of work : )
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Project is unsucesfull! Problem to stabilise MAX17687 iso buck regulator, bottom-right at the picture and all the things like linear regulators have problem with huge ripple, even LT3045 is unable to completelly remove noise from iso buck. I'm tried everything to stabilise iso buck but unsucesfull, so gan ddpd project going from beggining : (
If people are going to use SMPS for audio, usually they go to Meanwell for an off-the-shelf product. The output can be further filtered and regulated as desired, but its not too bad to begin with. https://www.meanwell.com/
Is Hypex SMPS400A180 too bad? There is some small noise I can see on smps pos and neg and going to think that all that noise is copied to iso buck and isolated linear regulators, is that possible? Have no idea right now whats going on with MAX, didn't identified isue. I will probably use small torus transformer for the isolated things and linear regulators, half bridge will be probably left on SMPS but hmm don't know right now
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Your problem may be caused by "polluted" ground as there does not seem to be any isolation between grounds. Is this the layout you are using? Have you posted the schematic?
Have you checked this: https://www.analog.com/media/en/technical-documentation/data-sheets/MAX17687EVKITA.pdf