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					            At Speed Production
             Testing of USB2.0
           480+Mb/s Transceivers
                 Dave Thompson
               Lucent Technologies

May 17, 2000                         2

  Signal Characteristics
  Characterization & Production Tests
  Test System Capabilities
  Special Test modes & hardware

May 17, 2000                             3
               Signal Characteristics

  Very low differential signal swings
       – 400-800mV
  High speed serial data rate
       – 480Mb/s
  Speed signaling
       – Detection of FS; LS; HS(CHIRP)
  Other Challenges
       – Jitter; Termination; Suspend/resume

May 17, 2000                                   4
               USB2.0 HS Signal Example
               480Mb/sec At-Speed Package Test

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               Characterization Tests

  Jitter testing
  At speed signal integrity
  Rise/fall time measurements
  Suspend current measurement
  Dynamic current measurement
  Squelch level measurement

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               Characterization Test:
               USB2.0 Data Eye

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               Typical Production Tests

  Fault coverage testing
  At speed functional testing
  DC parametric testing
  Speed detection testing
  Suspend/resume testing
  IDDQ testing

May 17, 2000                              8
                  Test System Capabilities

  Test system concerns:
       – Generate accurate waveforms < 800mV
       – Accurately receive signals < 800mV
       – Measure the “z” state
       – 480Mb/s data rates
       – Detection of FS; LS; HS(CHIRP)
       – Jitter; Termination; Suspend/resume
               HP F330 jitter test not adequate

May 17, 2000                                       9
                  Special Test:
                  Modes & Hardware

  Several on-chip test modes
       – IDDQ
       – PLL bypass
       – Suspend/Resume test mode
       – DFT reduces USB2 test complexities
               For example, speed signaling

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               Special Test:
               PLL Bypass Mode

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               Special Test:
               Modes & Hardware

  Utilize an HP F330
  Test system modifications:
       – Used paired drivers/comparators
       – Implemented fly-by; vt-divider
       – 4X mode for 400MB/s(Joergware)

May 17, 2000                               12
               Special Test:
               Clock/Data Recovery

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               Test Complexity
               Comparison: USB2.0 & 1394

               Test Type             Easier Same Harder
               At-Speed-Bypass         X
               At-Speed-Non Bypass                 X
               DC Parametric           X
               Suspend/Resume                      X
               IDDQ                          X

May 17, 2000                                              14
               At Speed Production Testing of
               USB2.0 480+Mb/s Transceivers
  Standard Digital Test System
  Custom Daughter Card not Required
  Typical production test equipment
   can test 480Mb/s components, for example:
       – Lucent’s USB2 Transceiver Test Chip

May 17, 2000                                    15

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