From: Lucie Linssen To: Leif Joensson , Luciano Musa , Jan Timmermans , Joachim Mnich , Ronald Dean Settles , Anders Oskarsson Subject: Re: TPC electronics Date: Wed, 2 Jul 2008 12:40:02 +0200 Dear all, I have discussed with Luciano and I give you below the outline of the situation and of our recommendations. -- about the preamplifier performance CERN (with the help of Helsinki and Takhiro Fusayasu) have tested the preamplifiers. The results have been presented at several occasions. The most recent presentation dates from the LCTPC phone meeting of March 19th 2008. http://ilcagenda.linearcollider.org/conferenceDisplay.py?confId=2624 CERN will collect all these presentations and make them available on a single web site. According to Luciano, the preamplifier works correctly in 11 out of the 12 modes of operation. Unfortunately there is a problem with the 30 ns peaking time mode. In this case the DC output of the shaping amplifier does not match the ADC range. Luciano expected that he could cure the problem by changing the top reference Voltage of the ADC to ~1.2 Volts. He made a test board to try this out. Unfortunately this did not bring the expected solution to the problem. Luciano would have liked to try some other solutions, but so far he has not found the time to do it. -- about the Front-end cards developed in Lund Luciano expects that the front-end card developed in Lund for operation with the 25 MHz ALTRO will function properly for 11 out of the 12 configurations (except 30 ns peaking time mode). He therefore suggests that that Lund equips the 2 boards with 25 MHz ALTRO's and preamplifiers and performs the system tests, prior to ordering the 800 additional preamplifier chips. -- about the 25 MHz ALTRO and the 40 MHz ALTRO The availability of 40 MHz ALTRO chips is not a problem. However, the collaboration should decide what they really need. If the collaboration decides to use the 40 MHz ALTRO, this is closely linked to the 30 ns peaking time mode. This would require finding a solution to the mismatch with the ADC. Luciano asks the collaboration whether this is really on their priority list. He recalls that, in view of the characteristics of MPGD signals, upon submission of the preamplifiers he was even prompted to provide much longer shaping times. Luciano therefore advices to first test the full system at the available peaking times (60 ns, 90 ns, 120 ns, unshaped operation) with 25 MHz ALTRO and with MPGD prior to going into the additional complication with the 40 MHz ALTRO and the short peaking time. -- about the order of the 800 preamplifiers At the time of preparing for the submission of the design of the preamplifier chip in May 2007, we asked the vendor to provide us with a quote for the production of 200 or 1000 chips. The difference between the 2 quotes was ~60 k$. Finally we placed the order for 200 chips only. At that time, we asked the vendor if we could later issue a new order for the supply of the differential of 800 chips, and what the cost would be. This was the answer from the vendor: -------------------------------------- We should be able to fabricate the additional 800 die (1000 die total) within one MPW run and initially provide the 200 die. The quote would then be updated to provide the 800 die at the delta in cost between line item 1 and 2 in quote 141869-A. ------------------------------------- According to this answer, the vendor should have indeed produced 1000 dies (chips) from the MPW of May 29, 2007, and kept the 800 chips not covered by our order waiting for a new order. Please note that their answer contains a "should", and therefore I cannot be guaranteed. We therefore propose the following parallel actions: -- CERN contacts the vendor to know the situation and get an updated offer; -- Jan and Leif decide on the mode of payment (sharing of the cost: All from "common fund"?, or are there other sources of income, like EUDET funds or so); -- Lund performs tests of the equipped front-end boards prior to the green light for the final order. With my best regards, Lucie In case you think this is easier to discuss over the phone, I can propose to set up a short phone meeting for tomorrow Thursday at 12 hrs. On Jul 1, 2008, at 4:07 PM, Leif Joensson wrote: > Dear Lucie, > > I would like to inform you that we send in the second prototype of > the FEC for > mounting of the components tomorrow (Wednesday 2.6.2008). We have had > two boards made and in a previous meeting with Luciano we agreed that > one of them should have the so called 25 MHz ALTRO chips, which we > received recently from CERN, whereas the other one should have the > 40 MHz ALTRO's. > Although promised by CERN a long time ago, we have not yet received > these chips. We have decided to have the boards completely equipped > except > for the 40 MHz chips on one of them. When we get the boards back we > will > send the one, which should contain the 40 MHZ chips to CERN for > mounting. > > I could also inform you that we have received the 25 MHz ALTRO chips > from Takeshi. > > I have not yet got any information about the status of the test > report which was promised > until middle of June (see mail from you below) which I guess have to > be evaluated before > the order of the remaining preamp chips is made. > We have also not got the RCU firmware which is needed to run at > sampling rates higher than > 10 MHz and which should be ready on the 6th of June (see mail > below). We are also waiting > for information on the reference voltages for the ALTRO. > > Best regards, > Leif > > Dear Leif, > > I discussed the list of deliverables requested from CERN with > Luciano Musa. We came to the following best-effort deadlines at > which he can provide them: > > > 1: The test report of the preamplifiers (results from Luciano, > Takahiro, Matti) => middle of June > > 2: Send the preamplifier chips to Lund => shipment will be prepared > by Antoine Junique over the coming ~1 week > > 3: Send ALTRO chips to Lund for second prototype => shipment will be > prepared by Antoine Junique over the coming ~1 week > > 4: Provide information on reference Voltages for the ALTRO => no > later than June 6th > > 5: RCU firmware modifications required to go from 10 MHz to 40 MHz > => this item is also needed for ALICE and will be ready approx. June > 6th > > > In parallel, we suggest that you also get in contact with Takeshi > asking him to send the 435 ALTRO chips, that CERN sent to Japan some > time ago, back to Europe. We seem to remember that he agreed to send > them to Lund. > > With our best regards, Luciano and Lucie