Difference between revisions of "MCE hardware"

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(MCEv2 5-MDM design notes)
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** Zero ohm resistors will not be used for connect ground planes, copper traces will be used
 
** Zero ohm resistors will not be used for connect ground planes, copper traces will be used
  
* ''' Low-noise bias lines '''  
+
* ''' MDM routing of low-noise bias lines '''  
 
How to divide up the Low Noise Bias Signals between the new Bias Cards.
 
How to divide up the Low Noise Bias Signals between the new Bias Cards.
 
** We need to maintain compatibility with existing Bias Cards which should ground these new backplane signal lines.
 
** We need to maintain compatibility with existing Bias Cards which should ground these new backplane signal lines.

Revision as of 23:46, 9 July 2008

MCEv2 5-MDM design notes

  • Jumpers
    • Jumpers for signal pairs have reference designators of JPn and JNn (eg. JP1 and JN1 are signal pair jumpers)
    • These jumpers are called out on the BOM as zero ohm resistors or DNP (do not populate) parts
    • Zero ohm resistors will not be used for connect ground planes, copper traces will be used
  • MDM routing of low-noise bias lines

How to divide up the Low Noise Bias Signals between the new Bias Cards.

    • We need to maintain compatibility with existing Bias Cards which should ground these new backplane signal lines.
    • Maximizing the number of Low Noise Bias Signals we could get 10 on each of BC1-BC3 for a total of 30.
    • How we route them to the MDM connectors is limited but we have a few options, what seems to be best to me is
      • P2 gets LN_BIAS_00 to 08
      • P3 gets LN_BIAS_09 to 15 (requires eliminating DET_BIAS_ORG and putting LN_BIAS_12 on this signal) P3 also has PXL_HTR
      • P4 gets LN_BIAS_16 to 23 with 1 spare signal
      • P5 gets LN_BIAS_24 to 29 with 3 spare signal