[time-nuts] ULN regulator with more current capability than LT3042?

[Peter Vince]

Please forgive this naive question, but I am concerned about the idea of
simply running two regulators in parallel.  Just like you don't put two
batteries in parallel, how do you ensure accurate load balancing between
the two?  I would worry that one of them, with a fractionally higher
voltage, would be driven into saturation, thus ruining any noise
isolation.  I must be missing something here?

     Peter


On 18 March 2018 at 22:43, Charles Steinmetz <csteinmetz at yandex.com> wrote:

> Tom wrote:
>
> Run two in parallel for twice the current and less noise?
>>
>
> This is actually a better solution than using an LT3045, for two reasons.
> First, as Tom noted, by paralleling two devices, the noise is reduced by
> sqrt 2 = ~1.4:
>
> "Designed as a precision current reference followed by a high performance
> voltage buffer, the LT3042 is easily paralleled to increase output current,
> spread heat on the PCB and further reduce noise -- output noise decreases
> by the square-root of the number of devices in parallel."  [LT Journal of
> Analog Innovation, v25 n1 Apr 2015]. <http://www.linear.com/docs/46398>
>
> Second, it reduces the dissipation of each regulator, so they run cooler.
> And as LT says, it allows spreading the heat on the board (but it is not
> advisable to put them too far apart).
>
> The primary disadvantage is that two 3042s cost about half again more than
> one 3045.  Also, board space may be a factor in some applications.
>
> So, unless you are extremely tight on board space or the ~1.5x cost
> increase is prohibitive, two 3042s in parallel are a better solution than
> one 3045 if you are seeking the lowest noise possible.
>
> Best regards,
>
> Charles
>
>
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