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[Gerard Visser <gvisser AT indiana.edu>]

hi Jianing,
        I checked the schematics

outer hybrid
https://drupal.star.bnl.gov/STAR/system/files/hybrid_outer_v2_3-schematic_0.pdf

inner hybrid
https://drupal.star.bnl.gov/STAR/system/files/hybrid_inner_v2_1-schematic.pdf

T-board
https://drupal.star.bnl.gov/STAR/system/files/T-Board_v3-schematic.pdf

	I think everything looks correct in these. One minor point is that we probably 
have to change the resistor values (on T-board and on hybrids) to have less 
reflection on the CLK and TRG lines. The cable has a characteristic impedance 
(differential) of around 100 to 110 Ohms. (It isn't very precisely controlled, 
we should measure it when we have the cable, but it will be around that value. 
So we should make the input impedance of T-board and hybrids assembly around 
100-110 Ohms. I suggest changing the resistors R1, R2 on outer hybrid and on 
inner hybrid from 49.9 to 78.7 Ohm, and the leaving the resistors R9, R10, R11, 
R12 on the T-board at 33.2 Ohm. Final values have to be confirmed after all the 
boards and cable are available for a scope measurement. At that time we _might_ 
decide to change the value on T-board; the 78.7 Ohm on hybrids is very likely to 
be fine (and is of course a lot more trouble to modify on existing boards, so we 
won't want to do that).
	[FYI in IST from the documents at 
https://drupal.star.bnl.gov/STAR/blog/yezhenyu/forward-silicon-tracker-ist the 
naively calculated input impedance 166 Ohms which is not right. I am not sure 
why, perhaps the documents are not really all correct. I think Ben did look at 
CLK & TRG waveforms with a scope and optimize these, although I don't have any 
record of it.]
	I will have a look at new outer hybrid layout for electrical / layout issues 
only -- not for mechanical interface issues -- but I expect no problems, it will 
look nice as the prior version did.
        Thanks,

                Gerard


On 10/31/2019 10:22 PM, 董家宁 wrote:
> Hi Gerard,
>    Thanks for your help.
>    There are no changes on the connector part.
>    Please let me know if you need any other files.
>    Thanks!
>
> Best,
> Jianing
>
>
> > -----原始邮件-----
> > 发件人: "Gerard Visser" <gvisser AT indiana.edu>
> > 发送时间: 2019-11-01 10:14:39 (星期五)
> > 收件人: star-fst-l AT lists.bnl.gov
> > 抄送:
> > 主题: Re: [Star-fst-l] Weekly FST meeting - 10/31/2019
> >
> > hi Jianing, Zhenyu,
> >         Somebody was going to document (simply with a picture or two) how 
> > that the
> > connector tab of outer (particularly) hybrid fits well to the T-board on
> > mechanical structure. I think we should see this before the new outer hybrid 
> > is
> > ordered. (Is there any change in this aspect of the new outer hybrid? I
> > understood no change.)
> >         Meanwhile, yes it is in my inbox to check the electrical aspects, I 
> > will try to
> > have that done by early next week.
> >         Thanks,
> >
> >                 Gerard
> >
> >
> > On 10/31/2019 10:04 PM, 董家宁 wrote:
> > > Dear All,
> > >
> > >     2.Hybrid, T-board:
> > >
> > >     With the help of Mike and Gerard,  the address connection for the 
> > > temperature
> > > sensor chip on outer hybrid is modified and updated.
> > >
> > >     And the schematic for T-board v3.0 is also updated (keep one set of
> > > temperature sensor and reset circuit).
> > >
> > >     I think they are all waiting for the double check.
> > >
> > >     If there are no other mistakes for outer hybrid layout, it will take 
> > > about 3
> > > weeks for the production.
> > >
> > >     All the detailed status are listed on the WIKI
> > > (https://wiki.bnl.gov/star/index.php/Hybrid_and_T-board).
> > >
> > >
> > > Best,
> > >
> > > Jianing
> > >
> > >
> > >      -----原始邮件-----
> > >      *发件人:*"Capotosto, Michael" <capotosto AT bnl.gov>
> > >      *发送时间:*2019-11-01 05:43:15 (星期五)
> > >      *收件人:* "Ye, Zhenyu" <yezhenyu AT uic.edu>, "star-fst-l AT lists.bnl.gov"
> > >      <star-fst-l AT lists.bnl.gov>
> > >      *抄送:*
> > >      *主题:* Re: [Star-fst-l] Weekly FST meeting - 10/31/2019
> > >
> > >      All,
> > >
> > >      As discussed last meeting, I’ve compiled the documentation and posted it 
> > > to
> > >      the wiki: https://wiki.bnl.gov/star/index.php/Cables
> > >
> > >      T-Board/Inner Signal Cable:
> > >
> > >      Last meeting we agreed we would use the IST-type of cables, due to cost. 
> > > It
> > >      turns out I misinterpreted the quote – we were quoted for 400ft of cable 
> > > but
> > >      they had a minimum 1,000ft order. It is cheaper as Gerard expected to use
> > >      the Polypropylene/PVC/PVC cable. I’m waiting to hear back from Gerard on 
> > > how
> > >      he’d like to proceed. The updated quotes binder mentioned can be found 
> > > here:
> > >      
> > > https://drupal.star.bnl.gov/STAR/system/files/Cable%20Quotes%20Binder%2010-28-2019.pdf
> > >      
> > > <https://drupal.star.bnl.gov/STAR/system/files/Cable%20Quotes%20Binder%2010-28-2019.pdf>
> > >      The quotes binder also includes new updated (non-expired) quotes, so 
> > > once we
> > >      have a decision we can order the cables. (Elke/Gerard/Zhenyu, will this 
> > > be
> > >      on one of the BNL accounts, or will I be sending this to someone else? 
> > > If it
> > >      will be on a BNL account I can start drafting the PO so it will be ready 
> > > to
> > >      send when we make a final decision).
> > >
> > >      Regarding the V2.1 T-Board modifications, I believe we just need to 
> > > remove a
> > >      handful of parts to in order to make it work, I’ve discussed this in an
> > >      email with Jianing and Gerard, and am waiting to hear back from Gerard. I
> > >      will have the cables re-labeled tonight before I leave (to match the VIA 
> > > REF
> > >      DES used in V2.1 T-Boards we are assembling). Once Gerard gives me the 
> > > O.K.
> > >      I’ll pull the parts off the boards, and we should be able to give them to
> > >      the assembler within a working day or two. If there are no objections, I
> > >      will extend the due date for the vendor to November 29.
> > >
> > >      If I’ve missed any points please let me know.
> > >
> > >      Best,
> > >
> > >            Mike Capotosto
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