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Re: Tracking fADC
Hi Gerard,
I've copied Simon in case he is not on the tracking-hw mailer to answer
the question about the number of Struck modules. The plan is to
assemble the boards by hand, so we will plan for 5 boards. Keep in mind
the lab is shutdown from 25 Dec to 3 Jan and I'm not sure how long it
will take to assemble the boards. I think it is no problem to work
around your travel plans to BNL, and the assembly will begin as soon as
we receive the boards/parts/documentation.
I agree [ and earlier review summaries agree ] that we need only two
types of fADCs. We updated the Gluex detector table in April '06 and it
reflects the two fADC plan. Recent discussions/decisions on the number
of channels per module clearly impact the number of modules/crates for a
given detector system, so as the detector groups decide we can update
the table. I noticed that the table does not list TDCs for the FDC
anode wires, but I believe this is something that needs to be
discussed/changed.
There are new quad channel 100Msps ADC chips out, and you are right,
these chips will have to be evaluated for power consumption, readout
modes[serial LVDS, parallel, etc], chip size, and of course cost.
I am reviewing the cost and schedule for the PED and Construction
spreadsheets that Elton posted to the portal for an upcoming review. I
admit, I do not know when the review is going to happen, but I will post
my findings to Elton before the holiday break.
Cheers,
Chris
(757)269-5053
~~~~~~~~~~~~~~
Gerard Visser wrote:
> Hi Chris,
> After further delays mostly due to other projects, I can now
> finally say the boards went to fab on 12/4. I expect to receive them
> on 12/15 (elected 7 working day turnaround).
> I will quickly evaluate one board here and send on to you several
> bare boards and parts. [And documentation, of course. I am finalizing
> that now.] Can you remind me, how many total Struck ADC's do we have?
> I seem to remember 5 200 MHz and 1 100 MHz, but maybe I remember
> wrong... Please check/clarify. If we have 6 Struck boards that is 6*8
> channels so I would propose to assemble 4 or 5 of the 16 channel
> amp/shaper boards. No point to committing parts to more boards than we
> have ADC's to read, although I am procuring parts for 8 amp/shaper
> boards per our MOU. Your tech will be assembling by hand, right?
> [There are no leadless or bottom-soldered parts on this board.]
> I can come to JLab in January to work with Simon to set up the
> amp/shaper boards and make measurements. I may have to travel to BNL
> for STAR setup activities, schedule depends on RHIC run schedule which
> is in flux still. We'll have to work around this, sorry.
> Pending a decision to use 24-channel (as opposed to 16-channel)
> granularity on the cables and the preamp boards, the tracking ADC
> module will be 72 channels rather than 64. This would be still on a 6U
> VME module (36 channels on main board and 36 more on a mezzanine). If
> I understand right, Dan & Simon and Fernando all basically agree to
> the 24-channel granularity.
> I don't think it makes much sense to have two different slow ADC's
> (65 & 125). We should settle on one sample rate. _If_ it turns out
> then that we use a part which is available also in a pin and
> functional compatible lower speed version, then we could consider
> saving some money this way. I think the costing should assume not
> doing this, at this point.
> The sample rate of the prototype ADC is not yet finalized. Based
> on request from Curtis it should be >100 MHz; as you note, that's what
> the detector electronics summary table shows too. I'll need to
> investigate the current market offerings and pick a sample rate not
> less than 100 MHz, based on the best that can be done today for
> maximum board density and minimum power. I suspect also this exercise
> will show that significant cost (and power ...--> cost again) savings
> are possible at some lower sample rates like 80 MHz. That was the case
> when I looked at this last, but it has been a while. I need time to
> look at the latest parts.
> Is the ADC board cost information needed by February per our Nov
> 16th phone conference, or much sooner?
> Talk to you later,
>
> Gerard
>
> C. Cuevas wrote:
>
>> Hi Gerard,
>>
>> A quick message to ask you about the amplifier/shaper boards and to
>> also ask you about the flash ADC design.
>>
>> We can begin assembly as soon as you send the amp/shaper board.
>> Please include any detailed drawings needed for SMD reference
>> designators etc. Presumably you will also send a bill of materials
>> with the 'kit'.
>>
>> I am tasked with reviewing the cost/schedule for the Hall D project
>> in preparations for a review. The GlueX detector 'table' shows a 12
>> bit 100Mhz design for the FDC and CDC. I know you are designing the
>> 64 channel fADC, but what is the sample rate for the prototype unit?
>> 65Msps? I have included the detector 'table' and know that there will
>> be two flash ADC boards. Some of the cost spreadsheets I am
>> reviewing show a 65Msps and 125Msps board so I will sort that out
>> with Elton.
>> Please reply or call at your earliest convenience,
>>
>> Chris
>> (757)269-5053
>> ~~~~~~~~~~~~~~~~
>>