[time-nuts] Low noise power supplies - dont' use Electrolytics

[gary]

Ceramic caps can be microphonic. Just something to be on the look out. 
Not so much with leaded ceramics, but more of a problem with surface mounts.

Tantalums are prone to overvoltage failure. Best to really overspec them 
regarding voltage.

Note that some LDOs are not stable with really low ESR bypass. There are 
app notes on this. I've stated my preference for p-fet pass devices, or 
better yet, shunt regulators. The PNP pass devices will need feedforward 
compensation if the ESR is too low.


On 11/27/2011 11:21 PM, Attila Kinali wrote:
> On Fri, 25 Nov 2011 22:25:37 -0800
> Chris Albertson<albertson.chris at gmail.com>  wrote:
>
>> One question:  How does one avoid using electrolytic caps if you need
>> (say) 1,000uF or even 100uF.   Those would be some mighty big film
>> caps.
>
> I think, aluminium electrolytics are meant, as these have a lot of
> "wear" and can die.
>
> Hence, you can use tantal or niob electrolytics, which have a dry
> eletrolyt.
>
> Or you can use ceramics which are already available at 100uF.
>
> 			Attila Kinali
>