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Digital Pilot & MCM 2003. Preliminary tests’ results. Andrea Boccardi PH/ED. Digital Pilot 2003. Old functionalities: OK New Functionalities (10 FastOR readout, new read-out scheme, ……): OK Optical power margins: ? SURPRISES!!!. DIGITAL PILOT’s CLKs. DIGITAL PILOT. Opt. CLK. Rx40.
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Digital Pilot & MCM 2003 Preliminary tests’ results Andrea Boccardi PH/ED
Digital Pilot 2003 • Old functionalities: OK • New Functionalities (10 FastOR readout, new read-out scheme, ……): OK • Optical power margins: ? SURPRISES!!!
DIGITAL PILOT’s CLKs DIGITAL PILOT Opt. CLK Rx40 10MHz read-out Logic 40Mhz Logic
Digital Pilot Analog Performances 40MHz clk
Digital Pilot’s Analog Performances Jitter 87ps > Jitter 10MHz (68ps)
MCM’s clock shape Clk40 on the ceramic MCM
The pilot is not capable of giving out a better clock? • With the electrical (LVDS) input the pilot is delivering a very neat clock. Jitter of 27ps!!!
Investigation’s Points • Problems in the optical chain • Change in the specification of the Rx40 in our system • Loss of current in the test PCB • Pin diode – Pilot compatibility • Power supply decoupling • Error in the Rx40 instance in the Digital Pilot • Noise injected on the lines (too low SNR)
Possible solutions • Get the pilot closer to the pin diode and move away the GOL • Place a stand alone Rx40 on the MCM as close as possible to the diodes and as far as possible from the pilot (already under test)
Total dose test Digital pilots have been tested up to 2Mrad: • No change in power consumption • No effect were found on the digital part • A degradation of the clock shape from optical input was noted since 200Krad but with a few days of annealing at room temperature the effect disappear
CERAMIC MCMelectrical test • Two Ceramic MCM have been tested: The 1st had a short on the power supply The 2nd has broken lines • The 2nd was recovered with some bricolage • The technology is known to have a low yield (50%) , all the MCM have been sent back for more, technology specific, tests
Functional test • On the recovered MCM functional test were performed showing full functionalities of the module • It is possible to program the Analog Pilot and the GOL via the Digital Pilot • The GOL is capable of locking and perform a reliable communication with only 16ps jitter • The clock has the mentioned problems • False SEU indicates possible problems due to the bad clock shape
G-Link measures • Even with the bad clock, the jitter on the optical communication is even better than the one on the previous MCM (GTL => CMOS ?) Jitter 16ps
CONCLUSIONS • The MCM is working digitally • The electrical problems are technology specific and will disappear in the SBU version • The clock recovery system must be improved: changes on the MCM are foreseen • The Digital part of the Pilot doesn’t show any effect due to radiation even at 2Mrad • SEU test must be performed on the Digital pilot (5 march 2004)