Star-fst-l mailing list

[Gerard Visser <gvisser AT indiana.edu>]

hi Li,
	Just a quick note to say I'll try to think about connector options but at this 
time, when my work for FST is still entirely without funding, it is unlikely 
that I can really attempt to search for an optimal connector. We hope the 
funding contract will be in place sometime soon.
	I do not believe that changing the connector incurs any real risk, except 
insofar as we don't really like the new type for some reason. Changing the 
layout is not risky, and adding additional layers to the T-board should that be 
necessary is not risky.
	I thought the connector used on IST should be ok; but if there is report that 
it broke (traces, presumably) under connect/disconnect we should think strongly 
about a better connector or layout. But I don't have info on such problems in IST.
        A smaller connector may exist, which could be helpful.
	A connector which affixes to the boards and may be the means of fastening the T 
board to the detector assembly, as with the SSD "T-board" that I showed, may 
exist. And I think it could be very helpful, in the case of both connectors on 
one side for easy connection of the T-board+cable.
	One which is both smaller and has mechanical features would be nice, perhaps 
there is something. That will be harder to find.
        The minimum pin count for connector from T board to hybrid by my 
reckoning is

8 for APV signals out
4 for CLK & TRG to APV
1 for RST to APV
2 for SCLK, SDA to/from(SDA) APV
1 for bias "SUB"
3 (more better) for VSS, GND, VDD

that is 19 min, better something like 24 or 26 or so. Not 44 for sure. There 
isn't any harm in 44 pins if you've got room for it though.
	(BTW I didn't remark on it before - sorry! - but looking at the latest posted 
schematic of the T board on 1/31, it seems the remote sense lines aren't 
connected on the T board as we'd planned on doing? Do I misunderstand there? Or 
else this needs some small change.)
        Sincerely,

                Gerard


On 2/15/2019 9:22 AM, LI YI wrote:
> Hi Gerard and All,
>
> Thank you for the documents!
>
> So the connector used in SSD is from
> http://www.nicomatic.com/product-amm_micro_connectors-81-en.htm
> Its pin size can go up to 50 pins. 44 pins are the minimum pins needed
> for FST. SSD connector pin distance is 1mm, which is larger than the
> previous one used in IST (which is 0.8mm). If SSD connector is more
> reliable than IST one, we can switch to SSD (the space saved would be
> small ~ 60/2*0.8mm-44/2*1mm = 2mm). Otherwise, we would prefer to use
> the same IST one to reduce the risk of error in drawing.
>
> Best,
> Jianing & Li
>
>
>
>
>
>
>
> On Thu, Feb 14, 2019 at 11:18 PM Gerard Visser <gvisser AT indiana.edu> wrote:
> > hi Li,
> >          Here for reference is info on the SSD "T-board" like thing, that was 
> > mentioned
> > in meeting discussion just now.
> >
> >          Gerard
> >
> >
> > On 2/13/2019 6:02 PM, Ye, Zhenyu wrote:
> > > Dear all,
> > >
> > > We will have a meeting to discuss Forward Silicon Tracker tomorrow at 9am BNL 
> > > time. The meeting agenda and bluejeans info can be found at
> > >
> > > https://drupal.star.bnl.gov/STAR/blog/yezhenyu/forward-silicon-tracker-weekly-meeting
> > >
> > > Best,
> > > Zhenyu