[sdiy] PCB op-amp layout - 2x2 or 1x4

[Tom Farrand]

Justin (et al),

I'm a fan of duals.  Yes, it costs you two more pins than the quad but
the power rails are on the "correct" side.  (Same side as a single.)
It takes me twice as long to plop the tracks down on a quad rather
than twin duals.  It is easier and much faster for my tiny brain to
route duals, than quads.  And then things get interesting with routing
power rails unless you flip the chip 180 degrees.  But that looks like
ass.  Having chips point the same way creates fewer building mistakes.
Like everything, it is all about tradeoffs you are willing or less
willing to make.

Peace.
Tom Farrand


On Thu, Oct 29, 2015 at 7:07 PM, Chris McDowell <declareupdate at gmail.com> wrote:
> Hey Justin,
>
> I prefer to use dual packages. SOIC dual op amps are easy to work with and space efficient, and breaking up the sections of the circuit usually keeps things more organized, for me.
>
> Chris
>
>> On Oct 29, 2015, at 1:25 PM, mark verbos <mverbos at earthlink.net> wrote:
>>
>> Justin,
>>
>> The big problem with the quad package opamps is that they are backwards in regard to power pins. Plus, the signal flow direction of them is out from the center, verses both the same direction on a dual. I haven't noticed a difference in performance, though.
>>
>> Mark
>>
>>
>>
>>
>> On Oct 29, 2015, at 12:59 PM, Justin Owen wrote:
>>
>>> I guess there's probably not a hard right or wrong answer to this - but, when laying out a tight PCB with a lot of op-amps - do you choose 2x or 4x op-amp packages?
>>>
>>> The 2x potentially gives you more placement flexibility - but increases overall parts count, the 4x decreases the part count but potentially leaves less room for routing traces between amps...
>>>
>>> ...thoughts on this from experience?
>>>
>>> Thanks,
>>>
>>> - Justin
>>>
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