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Minutes20161014

Robert Jordens edited this page Oct 9, 2017 · 3 revisions

present: @gkasprow, @sbourdeauducq, @dhslichter, @jordens, @jmizrahi, @jbqubit

minutes: @jbqubit

JESD204B waveform demo update provided by @jordens https://github.com/m-labs/artiq/issues/580

  • some bugs remain, 95% done
  • @jbqubit will test at UMD

NIST Servo Box and ARTIQ update by @dhslichter

  • relates to this https://github.com/nist-ionstorage/digital-servo
  • no current plans for SPI control of the lock box
  • Ion Storage has a rudimentary NDSP but not ready for export back to ARTIQ
  • does m-labs have a tracking system for keeping tabs on external groups that might have contributions to make back to ARTIQ? @jordens

Sayma LO mezzanine Idea proposed by @hartytp on 10/14 https://github.com/m-labs/sayma/issues/8

  • conclusion of those present on call: no separate LO mezzanine
  • common use case is high-frequency LO
  • this LO should be generated on low-loss analog mezzanine
  • @hartytp please comment

Sayma clock mezzanine signal/power @hartytp https://github.com/m-labs/sayma/issues/23

  • generate clock-specific voltages on mezzanine using LDO
  • conclusion: use same 30-pin header and power as analog mezzanine

100 MHz distribution discussion

  • crated new Issue #27
  • use LVPECL for faster edges, unclear if its also lower phase noise
  • use passive or active clock distribution?
  • @jordens suggests use of LTC6957 for LVPECL driver

power discussion led by @gkasprow

  • Sayma FPGA power needs to be generated somewhere, added to #22
  • @jordens points out that AD9154 needs DVDD12, CVDD12, PVDD12 = 1.3 V ± 2% to max out the spec; note this variation from usual 1.2V spec
  • make new Issue consolidating power requirements for various ICs
    • voltage, current, low noise or not
    • is this a job for michalgaska2@gmail.com?
    • full planning of power will happen during simulation stage
  • do we want hot-swap capability?
    • AMC handle contains micro-switch that works with MMC to kill power to board
    • decision: we want safe hot-swapping for both Sayma AMC and Sayma RTM
    • MMC will control two LEDs on AMC front panel

WUT and m-labs coordination on PCB testing

  • make Issue on this
  • WUT will
    • choose development board
    • learn to port ARTIQ to it
  • WUT needs
    • example of how to use ARTIQ for I2C
    • example of how to use ARTIQ for SPI
  • FPGA lead at WUT is Wojciech Zabolotny, wzab01@gmail.com, wzab
    • schedule discussion with WUT

sensor readout

  • reminder of past discussion: MMC is domain of WUT; MMC will be used to make crude temperature measurements of boards (I2C LM75); servo crate fans; protect against overheat
  • how are sensors readout by FPGA?
    • I2C multiplexor permits either AMC FPGA or MMC to do readout
    • MMC will write sensor values into AMC FPGA memory using SPI
  • create Issue discussing how ARTIQ will make use of sensors on PCB
    • which sensors need to be readout -- eg chip die temperature
    • readout frequency
    • where should the data go

analog mezzanine boards

  • agreed to add 2 SMP for 100 MHz clock for generation of LO on analog-mezzanine
  • noise specification for power to mezzanine boards discussed
    • @dhslichter did a study considering ADL5375 modulator and ERA-4XSM+ amplifier as sample parts, aimed for 1e-4 stability
    • initial conclusion: "10 mVpp DC 20 Hz to 20 MHz suffices", Greg says this is easy using switching supplies with no LDO
    • this conclusion is predicated upon use of ADM7150 or ADM7154 LDOs on the analog mezzanine; they give 40 dB isolation at 10 MHz (better at lower frequencies)
    • to be determined if LDO is needed after switching supply on the Sayma RTM motherboard or not; will be determined during power analysis; ACTION add a new Issue for power study tasks

CERN review

  • once the design layout is finished and inspected by physicists will be sent to CERN for review by Javier Serrano and others
  • CERN is likely interested only in AMC

timeline

  • Sayma RTM and Sayma AMC schematics will be ready by 10/20 @gkasprow
  • other schematics will be written while physicists review

TODO

  • @jbqubt add SMA wrench info
  • new Issue for analog mezzanines 1) 200 MHz 2) higher-frequency
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