Novena DVT to PVT ECO List
- 1 Novena DVT to PVT changes
- 1.1 ECO1: Fix Gig-E termination
- 1.2 ECO2: Remove FPGA clock termination
- 1.3 ECO3: Clarify D14D orientation
- 1.4 ECO4: Add clock margin to Gbit ethernet
- 1.5 ECO5: Swap switch to more robust and cheaper version
- 1.6 ECO6: 32.768kHz crystal EOL
- 1.7 ECO7: 12.0000 MHz wrong PN
- 1.8 ECO8: Clarify 47uF 1206 capacitor AVL
- 1.9 ECO9: FPGA SEEPROM is EOL
- 1.10 ECO10: Eliminate Audio Pop on Power-up
- 1.11 ECO11: Resolve 5V instability during power ramp with high voltage supply
- 1.12 ECO12: Resolve PCI-E double-series capacitor
- 1.13 ECO13: Bolster power to expansion card
- 1.14 ECO14: Fix DDC SCL buffer resistor value
Novena DVT to PVT changes
This is a list of all the changes applied to the board from DVT1 to PVT1 release. If it's not on this list, it didn't happen.
Each change has the format of issue summary/resolution, and specific change
ECO1: Fix Gig-E termination
KSZ9021RN refclk output pull-up drive is weak. Terminate with a 300-ohm pull-up, instead of the proposed AC termination network.
|R20S 49.9, 1% / REC1005N||DNP||Gigabit ethernet|
|C16S 2200pF, X7R, 50V, 10% / CAPC1005N||DNP||Gigabit ethernet|
|added||300, 1% / RES1005N||Gigabit ethernet|
ECO2: Remove FPGA clock termination
Use internal FPGA differential termination for clock. Electrically superior to discrete solution.
|R57B 100, 1% / REC1005N||DNP||FPGA|
ECO3: Clarify D14D orientation
Added fab note on bottom silkscreen layer (outside PCB but inside assy dwg) to indicate that D14D is a side-firing LED. Fab was orienting LED accidentally as vertically firing LED.
ECO4: Add clock margin to Gbit ethernet
RGMII spec assumes an extra 10 inch delay added to the clock wire versus data wire, required to be implemented on the PCB. This is software-compensated by tweaking PHY parameters in the Micrel PHY, but we add these delay line options just in case that option turns out to be unworkable.
TXC line gets 5" added by default in this configuration because it's impossible to measure if the TXC line is adequately delayed and out of paranoia we split the difference.
|Added||R24G 0 ohm / RES1005N||RX clock path (0 inch option)|
|Added||R22G 0 ohm (DNP)||Rx clock path (5 inch option)|
|Added||R23G 0 ohm (DNP)||Rx clock path (5 inch option)|
|Added||R30G 0 ohm (DNP) / RES1005N||TX clock path (0 inch option)|
|Added||R28G 0 ohm||Tx clock path (5 inch option)|
|Added||R29G 0 ohm||Tx clock path (5 inch option)|
|Added||R27G 0 ohm||Tx clock path (5 inch option)|
|Added||R25G 0 ohm (DNP)||Tx clock path (10 inch option)|
|Added||R26G 0 ohm (DNP)||Tx clock path (10 inch option)|
In addition to these components, a trace is run through the PCB adding these delays.
ECO5: Swap switch to more robust and cheaper version
Change out switch to pushbutton type available via HQB. No change in PCB, just BOM swap.
|SW11B TS-1187A, Chi Fung (DNP)||TL3342F160QG/TR (DNP)||or equiv (see trigger on chibitronics)|
|SW10B TS-1187A, Chi Fung||TL3342F160QG/TR||or equiv|
|SW10S TS-1187A, Chi Fung||TL3342F160QG/TR||or equiv|
|SW11S TS-1187A, Chi Fung||TL3342F160QG/TR||or equiv|
ECO6: 32.768kHz crystal EOL
Swap out Y11B for part that is not slated for EOL. This does involve a footprint swap.
|Y11B ABS10-32.768KHZ-7-T 7pF CL||ABS06-32.768KHZ-T 12.5pF CL|
ECO7: 12.0000 MHz wrong PN
The part numbers for Y10U and Y11U are for the wrong package size.
|Y10U 12.0000 MHz (SaRonix-eCera F9, 30ppm, 8pF)||12.0000 MHz (NDK NX5032GB-12MHZ-STD-CSK-5, 30ppm, 8pF)|
|Y11U 12.0000 MHz (SaRonix-eCera F9, 30ppm, 8pF)||12.0000 MHz (NDK NX5032GB-12MHZ-STD-CSK-5, 30ppm, 8pF)|
ECO8: Clarify 47uF 1206 capacitor AVL
The wrong package type (1210) is being ordered for this 1206 part. Added a suggested AVL to prevent this problem from happening in the future.
|C43M 47uF, 6.3V, 20% X5R||47uF, 6.3V, 20% X5R (CL31A476MQHNNNE)|
|C44M 47uF, 6.3V, 20% X5R||47uF, 6.3V, 20% X5R (CL31A476MQHNNNE)|
|C45M 47uF, 6.3V, 20% X5R||47uF, 6.3V, 20% X5R (CL31A476MQHNNNE)|
|C18M 47uF, 6.3V, 20% X5R||47uF, 6.3V, 20% X5R (CL31A476MQHNNNE)|
|C52C 47uF, 6.3V, 20% X5R||47uF, 6.3V, 20% X5R (CL31A476MQHNNNE)|
ECO9: FPGA SEEPROM is EOL
The SPINOR SEEPROM on the FPGA has been obsoleted. Replace with a current part number.
ECO10: Eliminate Audio Pop on Power-up
The speakers make an audible pop on power-up (despite the amps being anti-pop). Add resistors that enable independent muting of the speakers from the audio codec.
|Added||R28A 0 ohm||KEY_ROW1 now used to control amp power-down|
|Added||R30A 0 ohm (DNP)||backup option in case the above doesn't work|
|Added||R33A 100k, 1%||Pull-down to ensure PA starts in mute state until CPU I/O is initialized|
ECO11: Resolve 5V instability during power ramp with high voltage supply
Power supplies with voltage greater than 12V have an inconsistent power-on behavior. This is due to some sort of extra noise or ringing on the 5V regulated line during the first few ms of power-on. Resolved by adding an extra 22uF capacitance on the output node, verified via oscilloscope (no ringing leading to shutdown visible).
|C22N 22uF, 10V, X5R, 20% (DNP)||22uF, 10V, X5R, 20%|
ECO12: Resolve PCI-E double-series capacitor
PCI express diff pairs are AC coupled. The convention, it turns out, is for the Tx side to have the capacitor. I had incorrectly assumed that the convention was to put the caps on the motherboard side. Correct this by replacing caps with 0 ohm jumpers.
|C21X 0.1uF, 6.3V, X5R 0201||0 ohm 0201|
|C22X 0.1uF, 6.3V, X5R 0201||0 ohm 0201|
ECO13: Bolster power to expansion card
Expansion card power budgets are now exceeding 7.5W. Bolster the power budget by an additional 10W by adding a leaf-spring power connector.
Two options are provided for, one via a Wurth 331051472057 leaf-spring connector, and one via a Millmax 0990-3-50-20-75-14-11-0 pogo-pin style connector. Both are one-sided contacts, rated for about 2A max. These connectors go on the expansion board side -- this ECO simply provides for an open, gold landing area for these headers.
No ground connector is provided because there are ample grounds provided on the connector already.
ECO14: Fix DDC SCL buffer resistor value
R33L, the pull-up on the NMOS inverter designed to prevent trivial DoS attacks via HDMI port, is too weak. Strengthen it so that the circuit operates.
|R33L 47k, 1%||4.7k, 1%|