To clarify, the IRAUDAMP7D BOM shows 1N4003 for D5-6, whereas the IRAUDAMP7S BOM that you provide the link for shows MUR120. It's probably a moot point now.We dont read the same bomI read page 33 of IRF ref design. D3, D5, D6 are supposed to be mur120.
yes that's missing. I started the job. Did not yet identify them all.
The parts ref are those from the IRAUDAMP7S reference design, page 30. It's a L25D board picture.
An externally hosted image should be here but it was not working when we last tested it.
it's a preview of work in progress and there might be errors at this stage. I just found one
A question at this stage :
The reference design BOM recomends ultra-fast switching diodes for D3, D5, D6.
The kit comes with 1N4007 which are not known to be ultra-fast.
Is this something to worry about ?
You can be assured.Component configuration of the tube model UF4004, VISHAY, or MIC.
Parameters, it is the recovery time is 35NS. And MUR120 are the same.
Otherwise stated 22UF capacitor, they work within the regulator DC15V.
Pressure values of more than 25V fully meet the need. Higher withstand voltage of the capacitor in order to reduce the capacitor the ESR.
That's interesting; are you sure about that?
I would have thought the opposite, because if you make a 50 V cap from two 25 V caps by connecting them in series, the ESR is doubled.
I don't know exactly how they make higher voltage caps, but one way would be with thicker dielectric material, and that would increase ESR.
Capacitor of the same capacity. The greater the pressure, the greater the volume.
Height is inversely proportional to the ESR and capacitance when the capacitor height is higher, the internal anode aluminum anode paper, the greater the electrolyte area.
The smaller the impedance.
Attachments
thanks ljm.
the picture you copied above is the work in progress version. I wish I could edit the posts and remove it to avoid confusion!
The final and correct one is here : L25D board with parts cross reference
@cwier60 :
the picture you copied above is the work in progress version. I wish I could edit the posts and remove it to avoid confusion!
The final and correct one is here : L25D board with parts cross reference
@cwier60 :
thanks ljm.
the picture you copied above is the work in progress version. I wish I could edit the posts and remove it to avoid confusion!
The final and correct one is here : L25D board with parts cross reference
@cwier60 :
I hope you can smoothly
Bridging is "not supported" on the L20D equivalent in the reference design document(links to it are elsewhere on this thread or on the L15D thread), and the L25D is even higher power than it (a variant not discussed in the Ref Doc).
I'm not sure what would happen, but if the components are not capable of handling the load, it would probably end unhappily....
The L15D on the other hand should support bridging (500W@8ohms). The Reference Doc provides a bridging circuit..
Thanks for answer
The Reference Design shows the bridged rating for 8 ohms only.. so I would suspect no.. (4 and 2 are probably too low, something is going to loose its magic smoke..
Remember that in a bridged amp, it is as if each half-bridge "sees" half of the load. Bridged amps usually target 8ohm and more loads. They rarely support 4ohms or you would have to drastically limit the power. Opposite to your goal.
isn't L25D an exact implementation of IRAUDAMP7S as in page 30 of the ref doc with two fets per channel ?
http://www.inductor.com/irf/iraudamp7s.pdf
re-read my sentance above. really unclear
to make it simple, it seems to me that 2xIRFB4020 mosfets are functionnally equivalent to 1xIRFI4020 half-bridge integrated package.
Do I miss something ?
Yes functionally the same, however you missed something
IRF4020H-117P = Id at 100 deg C = 5.7 Amps Cont.
http://www.irf.com/product-info/datasheets/data/irfi4020h-117p.pdf
IRFB4020PBF = Id at 100 deg C = 13 Amps Cont.
http://www.irf.com/product-info/datasheets/data/irfb4020pbf.pdf
You should see the Pd numbers, its almost shocking to see the difference between the two.
This is why I am a fan of the L25D from LJM and the L25DE from hien.t.nguyen for use with 8 Ohm speakers
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I believe the THD and noise floor is better with the L15 per LJM, you can get more power from L25 into 4 ohms, you better have a larger heatsink or a fan. I think you could blow away the power nameplate rating with proper cooling. The only drawback I see to the IRS designs is the heatsink is central to the board, menaing when really pushing it for long periods a fan is necessary. I am going to do a multichannel IRS amp using one of the two design mentioned above, my hangup is the fets not being moved to the perimeter like the LM3886/4780 kits
