FMC ADC 100M 14b 4cha - Hardware issueshttps://ohwr.org/project/fmc-adc-100m14b4cha-hw/issues2019-12-03T14:14:42Zhttps://ohwr.org/project/fmc-adc-100m14b4cha-hw/issues/64V5 - Replace LEMO connectors by backwards compatible type2019-12-03T14:14:42ZErik van der BijV5 - Replace LEMO connectors by backwards compatible typeWhen going from V6 to V5 the LEMO connector type has been changed from EPL to EPK.
The EPK type is compatible to the EPL-type used before.
**V6**
- https://edms.cern.ch/file/2258651/1/EDA-02063-V6-0_pcb-mat.pdf
- J5 EPK.00.250.NTN (09.46.11.180.6)
- https://www.lemo.com/pdf/EPK.00.250.NTN.pdf
**V5**
- https://edms.cern.ch/file/1165461/1/EDA-02063-V5-0_pcb-mat.pdf
- J1-J5 EPL.00.250.NTN (09.46.11.180.6)
- https://www.lemo.com/pdf/EPL.00.250.NTN.pdf
The CERN SCEM item number is the same and now the Stores catalogue shows the one used in V6: EPK.00.250.NTN
https://edh.cern.ch/edhcat/Browser?command=searchItems&scem=09.46.11.180.6#
The EPK has liberated some space in the housing and makes it looks like that the corner pins are on some feet.
The connector body therefore no longer touches the board, and prevents short circuits on some designs. EDA-02063 may use both types.
![LEMO](/uploads/3664a5b97b4ab4446e235cbfa34c5a24/LEMO.png)V6.0Erik van der BijErik van der Bijhttps://ohwr.org/project/fmc-adc-100m14b4cha-hw/issues/9V5 - Solder leaks through non-capped area under ADC component2022-03-21T08:55:58ZErik van der BijV5 - Solder leaks through non-capped area under ADC componentAs the holes in the copper/gold-plated area under the ADC component are
not capped and filled, solder is leaking through it.
Visually it is not appealing (see attached file), while it may cause
(unlikely though) that the connection between the copper plate under the
DAC IC and the PCB may not be made in the best way as solder may have
leaked away.
It was suggested by a production company to use Capped and Filled vias
in this area. This is actually done on the Fine Delay card too
(capped-and-filled under 5 ICs, no solder mask over the areas).
Note that cap-and-fill is very expensive (\> 50 CHF/board?) and may well
be overkill in this case. A soldermask over the area will fill the holes
enough to prevent the solder from leaking through, but may slightly
increase the temperature.
See also:
- https://www.ohwr.org/work_packages/459 (ADC)
- https://www.ohwr.org/work_packages/580 (Fine Delay)
### Files
* [photo.JPG](/uploads/340cc6c7a2c47c77797be390d5041a3c/photo.JPG)V6.0Erik van der BijErik van der Bijhttps://ohwr.org/project/fmc-adc-100m14b4cha-hw/issues/10V5 - Replace FMC front panel kit2019-11-08T18:33:11ZProjectsV5 - Replace FMC front panel kitReplace the Xtech FMC front panel kit, the two spacers and the four
hexalobular screws by the following ELMA kit reference:
21M280-2
[ELMA 21M280-2 datasheet](http://www.elma.com/-/media/product-files/enclosures-and-components/front-panels-and-digital-printing/files/ch15-datasheet-fmcmezzaninefrontpanels-e.ashx) - see section "Scope of delivery" as the table in the datasheet is not complete.
The ELMA 21M280-2 kit contains:
- 1 FMC front panel
- 1 O-ring
- 2 10mm spacers
- 4 M2.5x6mm screws
---
V6.0Erik van der BijErik van der Bijhttps://ohwr.org/project/fmc-adc-100m14b4cha-hw/issues/13V5 - update data for Si5702019-11-08T18:28:31ZErik van der BijV5 - update data for Si570In the BOM the Silicon Labs 570BBC000121DG is described as a generic
component without the specific startup frequency mentioned:
- Description: 10-280MHz 3.3V ±20ppm LVDS Any-Rate I2C Programmable XO
Oscillator Si570 Serie
- Val\&Device: 10-280MHz -- to change to 100.000000 MHz
- Manufacturer P/N: SILICON LABS 570BBC000121DG
Correct the BOM to include the startup frequency of 100.000000 MHz. This
likely needs an update of the symbol in the schematics.V6.0Erik van der BijErik van der Bijhttps://ohwr.org/project/fmc-adc-100m14b4cha-hw/issues/22V4 - May possibly reduce crosstalk by removing shields or adding vias2019-11-08T18:20:33ZErik van der BijV4 - May possibly reduce crosstalk by removing shields or adding viasOn layer 1 of the PCB, near the ADC, there are copper islands to
separate the input signals. By removing them (scratching away) one may
try to see if these islands are not counterproductive.V6.0Erik van der BijErik van der Bij