Asynchronous I2S FIFO project, an ultimate weapon to fight the jitter

Ian,

You are an exception to none, one of the most valuable members of the DIY community.

Thank you!

Thanks ryanj, my pleasure! This community brought me more than what I did. I shall say thank you to you all :).

Just wish your are the diyAudio moderator, they even don't accept my article about FIFO for no reason :D. My friend George and me spent a lot of time on it :(.

Regards,

Ian
 
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did they say they didnt accept it, or just not reply? how about you send it to Jan Didden, who is responsible for Linear Audio which has been going from strength to strength, the latest edition is packed with excellent articles from people like Walt Jung, Scott Wurcer etc. still hasnt got a PDF version, but distribution is getting wider and wider. perhaps then DIYA will accept your article =P. I'm on speaking terms with a few of the Mods, want me to see if I can get it noticed? they are all pretty busy and simply may not have had the time.

Salas might be a good person to contact about it actually
 
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Ian,

Got the isolater board thank you. Looks great - even the board is cut where the isolation occours:)

I will place the component order for this and the battery management board these days and I also think it is time for me to invest in a dedicated smd rework station (OT: any <200$ suggestions would be welcome by PM)

Cheers,

Nic
 
Ian

Received the isolator board yesterday and soldered all the components today. Connected it to FIFO and clock board, use separate batteries (2xLiFe=6.6V) for clock and FIFO. All LEDs "on" but the SPDIF input card not function. Remove the isolator board, everything fine. Voltage to the ICs on the isolator board are 3.2XXV. While still finding the fault, smoke came out from the clock board:(, a component next to the FIFO letters on fire!!!Looks like a capacitor.

What shall I do?
 

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did you make the necessary adjustments to the clock board to use an independent supply?

that actually looks like an inductor, but I dont have the board with me at te moment

yeah lifepo4 batteries dont exactly have a current limit.... myself i'll be testing with inline fuses unconnected to the fifo board first. i'll have a think and look over the isolator board BOM/schematic, but in the meantime can you explain how exactly you supplied power?
 
yep, you didnt prepare the clock board

it is indeed an inductor, its L11,..the one you are supposed to remove before applying independent power....

whoops

from the clock board manual

- J5, Optional DC input, (do not use if interface with FIFO board normally)
Optional independent DC power supply input for Dual XO Clock Board. FB L11 has to be removed before use this DC
 
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That doesn't explain why it didn't work with the isol board in the circuit though does it? I was reading this part of the manual today and the way I read it you shouldn't need to remove L11 when using the isolator board, only if powering the two boards separately, which is when the issue came up evidently. This is because you've got 5V supply from the FIFO regulators and 6.6V supply from the battery both connected to the same clock supply rail ...
 
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yep, you didnt prepare the clock board

it is indeed an inductor, its L11,..the one you are supposed to remove before applying independent power....

whoops

from the clock board manual

I thought if I connect the clock board directly with FIFO and want to use individual supply for the clock , then I need to remove it. With the isolator board in between, I don't think I have to.
 
erm, I would reassess my understanding given the evidence at hand =) given its the one part that was vaporised, i'm thinking there was a problem with it being there...

why would it matter if the iso board is there? you are still connecting 2 parts of the circuit that are assumed unconnected. without the board here or a schematic its hard to say. but i'm guessing its because L11 provides a path from the clock power supply, which would normally be coming from the fifo board, but since this line isnt used or transmitted with the isolator due to separate power being assumed, it now may connect to ground
 
there may be another problem, maybe i'm wrong here (its been known to happen) it just seems a bit coincidental that L11 and only L11 (as far as we know at this point... we hope) said goodbye. I went back and read that post by ian and it does read that way in post 1160. but hes talking about removing the clock LDOs, shorting across them and then using J5 to directly power the clocks with a 3v3 battery. you have a different situation here, your LDOs are still in place yes?
 
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there may be another problem, maybe i'm wrong here (its been known to happen) it just seems a bit coincidental that L11 and only L11 (as far as we know at this point... we hope) said goodbye. I went back and read that post by ian and it does read that way in post 1160. but hes talking about removing the clock LDOs, shorting across them and then using J5 to directly power the clocks with a 3v3 battery. you have a different situation here, your LDOs are still in place yes?

Yes, the LDO still in place. The clock board LED still on when it burnt.
 
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Actually looking closer L11 may be powering the clock board side of the isolator via pin 9 on J9, in that case it could have been a short anywhere on the clock side of the isolator that caused that. can you disconnect the isolator and test resistance from pin 9 to ground (pin 10 or 6) on J9 (isolator board output FFC header) and tell me what you get? it should be open circuit
 
ah actually it wont be open as the regulator input bypass cap and the reg itself will interfere, but if you have a short or a low resistance then we have our answer

thank god, Ians here to the rescue (name down bottom, hello Ian!) since I dont have the fifo here, or the schematic i'm flying blind, but still trying to help
 
Actually looking closer L11 may be powering the clock board side of the isolator via pin 9 on J9, in that case it could have been a short anywhere on the clock side of the isolator that caused that. can you disconnect the isolator and test resistance from pin 9 to ground (pin 10 or 6) on J9 (isolator board output FFC header) and tell me what you get? it should be open circuit


That's what I just came back to write ...


I'd be checking around U3, C4 and L1, just a hunch.

Do the same test on J4 of the clock board, before hooking anything up again, just to be sure.
 
Actually looking closer L11 may be powering the clock board side of the isolator via pin 9 on J9, in that case it could have been a short anywhere on the clock side of the isolator that caused that. can you disconnect the isolator and test resistance from pin 9 to ground (pin 10 or 6) on J9 (isolator board output FFC header) and tell me what you get? it should be open circuit

It's 4.37K
 
nothing connected to the board? is that a steady value? that seems pretty low given you are measuring across an LC filter with an inductor in series and a 10uf cap to ground. other than checking the parts mentioned above by hochopeper L1, C4, L2 and U3 i'm out of ideas given I dont have schema, or board here. hopefully Ian pipes up shortly, sorry I couldnt be of more help
 
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