[sdiy] Problems with linearized SSI2164 ?
dlmanley at sonic.net
Thu Feb 14 20:49:22 CET 2019
On February 14, 2019 5:37:45 AM PST, Mattias Rickardsson <mr at analogue.org> wrote:
>On Thu, 14 Feb 2019 at 00:54, Neil Johnson <neil.johnson71 at gmail.com>
>> > In any case, I believe that the circuit Dan was using it in is
>> > one given by Phillip Gallo in the datasheet, and it ain't working.
>> > tells me that the ICs are defective.
>> In this case, no - the circuit as built by Intellijel was not as
>> Gallo designed, as the loop compensation capacitor was wrong but a
>> of 5ish (22p vs. 100p).
>I'm glad the error was found and the mystery finally understood! :-)
>HF oscillations seems to be one the most common mistakes we all make,
>then fail to realize for a while, blaming everything else around it
>the behaviour ends up wonky.
>I've tested the SSI2164 as drop-in replacement in as many applications
>could and haven't been able to find any differences in behaviour -
>for generally better performance in THD & SNR. So I agree:
>But you're right about one thing: *Good job SSI!*
This is a GBW/ phase margin issue? Indicating the SSI part has greater GBW so is less tolerant to a reduced cap value?
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