Novena EVT to DVT changes

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Revision as of 10:07, 19 March 2013 by Bunnie (talk | contribs) (Inrush current limit)
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Novena EVT to DVT changes

This is a list of all the changes applied to the board from EVT1A to DVT1 release. If it's not on this list, it didn't happen.

Each change has the format of issue summary/resolution, and specific change

Inrush current limit

The RC constant governing the turn-on/turn-off rates of the FET power switches needs tuning. In EVT, most switches are turning on too quickly for them to be effective. Resolution is to increase capacitance and resistance.

EVT DVT Notes
R38N 330, 1% / REC1005N R38N 10k, 1% / RESC1005N P3.3V_DELAYED
C30N 0.1uF, 6.3V, X5R / CAPC0603N_B C30N 1.0uF, 25V, 20% X5R 0201 / CAPC0603N_B P3.3V_DELAYED
R29N 330, 1% / REC1005N R29N 10k, 1% / RESC1005N P5.0V_DELAYED
C27N 0.1uF, 6.3V, X5R / CAPC0603N_B C27N 1.0uF, 25V, 20% X5R 0201 / CAPC0603N_B P5.0V_DELAYED
R11H 330, 1% / REC1005N R11H 10k, 1% / RESC1005N SATA_PWRON
C10H 0.1uF, 6.3V, X5R / CAPC0603N_B C10H 1.0uF, 25V, 20% X5R 0201 / CAPC0603N_B SATA_PWRON
C10X 0.1uF, 6.3V, X5R / CAPC0603N_B C10X 1.0uF, 25V, 20% X5R 0201 / CAPC0603N_B PCIE_PWRON
R15L 1k, 1% / REC1005N R15L 10k, 1% / RESC1005N LCD_VCC_SW
C14L 0.1uF, 6.3V, X5R / CAPC0603N_B C14L 1.0uF, 25V, 20% X5R 0201 / CAPC0603N_B LCD_VCC_SW
C19L 0.1uF, 25V, X5R / CAPC1005N C19L 1.0uF, 25V, 20% X5R 0201 / CAPC0603N_B LCD_BL_VDD

FPGA boot fuse interference

FPGA's internal pull-ups on boot will yank boot fuses to the CPU, causing wrong boot source to be selected.

EVT DVT Notes
R12F 4.7k, 1% / REC1005N R12F 4.7k, 1% (DNP) / RESC1005N depop pull-down
R13F 4.7k, 1% (DNP) / REC1005N R13F 4.7k, 1% / RESC1005N populate pull-up

Gbit Ethernet Reset

Default circuit recommended by reference design is bogus. Get rid of it.

EVT DVT Notes
C32G 10uF, 10V, X5R, 20% removed
D11G BAT54T1G removed
D12G BAT54T1G removed
R20G 10k, 1% R20G 10k, 1% (DNP) also changed to pull to ground by default


  • remove R11X, tie gate of Q10X to P3.3V_DELAYED (off of pin 2 of Q11X) (resolve PCIE power on issue)
  • remove R14G (possibly resolve magnetics termination issue)
  • replace R21G with 0-ohm resistor or shunt (partially resolve Gbit refclock stability issue)
  • move R28L to R27L (HDMI HPD swap)
  • add Q17L (HDMI HPD swap)
  • add R29L (HDMI HPD swap)
  • change R21A from 100 ohms to 10 ohms (see if others need changing)
  • APX803-44SAG-7 added, monitoring the P5.0V line, and pulling down the RESETBMCU line.
  • add 2.2k resistor in shunt with input capacitor network (BATT_PWR to ground)
  • Cut ALRCK trace to U11A, and jumper pin 9 of U11A to LCD_BL_ON
  • Rewire LCD_BL_ON to a new GPIO on the i.MX6 (final GPIO TBD)
  • Connect PICE_PWRON to i.MX6 (final GPIO TBD)