[sdiy] Tempcos of Xicon and LCR polystyrene caps

[Andre Majorel]

On 2006-06-14 19:19 -0600, Ian Fritz wrote:
> At 03:24 PM 6/14/2006, Andre Majorel wrote:
>
> >The LCR FSCEX polystyrene caps are five times more expensive. That
> >may be because they are more precise (1% vs. 5% for the Xicon
> >parts) but they also claim -50/+110 PPM/°C.
> 
> Do you have a link for LCR?  I can't seem to find them.  Thanks.

I mangled the name. It's really "FSC/EX". Farnell have a data
sheet online :

  http://www.farnell.com/datasheets/43416.pdf

> >The Panasonic ECHS PPS (*not* PS) caps perform as well as the LCR
> >FSCEX (i.e. 0.04 Hz/°C at 440 Hz) for slightly lower price.
> 
> Polyphenylene sulfide.  Has anyone tried these in VCO applications?  They 
> seem a bit lossier than polystyrene.

Paul used one in the MOTM-320 VCLFO (that's how I knew about them)
which goes down to 2 mHz. He says in the doc that PPS has "very
low leakage current" and is fine at LF but unsuitable for a VCO
because it's not so good at HF.

The VC vs. frequency curve of that circuit might sag in the left,
though. I don't suppose many customers would complain that their
LFO is running at 9.2 mHz instead of 9.1 mHz.

Ah... Nothing like starting the day with a good troll.

-- 
André Majorel <amajorel at teaser.fr>
http://www.teaser.fr/~amajorel/