FMC ADC 100M 14b 4cha - Hardware issueshttps://ohwr.org/project/fmc-adc-100m14b4cha-hw/issues2019-11-08T18:38:57Zhttps://ohwr.org/project/fmc-adc-100m14b4cha-hw/issues/8V5 - Specify Phillips screws instead of Hexalobular type2019-11-08T18:38:57ZErik van der BijV5 - Specify Phillips screws instead of Hexalobular typeThe [mechanical
BOM](https://edms.cern.ch/file/1165461/1/EDA-02063-V5-0_arrangement-mat.pdf)
specifies "Hexalobular Pan Head Screws".
(BN 5687 ISO 14583 - Hexalobular Pan Head Screws - Fully Threaded -
Stainless Steel A2 M2.5 - L=6mm BOSSARD - 3061597)
However, the Xtech and ELMA FMC front-panel kits both contain Phillips
screws. Also it is more practical to use Phillips screws.
Improve BOM. Copy info from
[FMC\_Delay\_1ns\_4Cha](https://edms.cern.ch/file/1382769/1/EDA-02267-V6-0_arrangement-mat.pdf)
BOM. And improve as those specify that the screws are in the kit, but do
not specify the type at all (just
[pan-head](http://en.wikipedia.org/wikis/Screw#mediaviewer/file:screw_head_types.svg)
(image A).V6.0Erik van der BijErik van der Bijhttps://ohwr.org/project/fmc-adc-100m14b4cha-hw/issues/11V5 - Add soldermask both sides near standoff2022-03-21T08:55:35ZErik van der BijV5 - Add soldermask both sides near standoffIn the corner near standoff B4 there is no soldermask on copper areas on
both sides of the board. The idea was that this should improve the
cooling in this area that gets hot because of the regulator in this
corner. However, as there is no soldermask, the solder for the
components is leaking out (see attached images) which can create
problems.
As the surface is so small anyway, we believe it is better to add the
soldermask.
- Add soldermask on both sides near the B4 standoff to improve
solderability.
### Files
* [IMG_1176.JPG](/uploads/985199534940fcc16f4837de812066ad/IMG_1176.JPG)
* [IMG_1180.JPG](/uploads/ef42e4d7f10e0f5552d0c5fbca300852/IMG_1180.JPG)V6.0Erik van der BijErik van der Bijhttps://ohwr.org/project/fmc-adc-100m14b4cha-hw/issues/14V5 - Noise level channel 1 higher than others2022-03-04T14:19:39ZErik van der BijV5 - Noise level channel 1 higher than othersThe noise level of channel one is in the +/- 50mV range is around a
factor of 3 (~5dB) higher on channel 1 than on the other channels. This
is likely caused by this channel being closest to the DC/DC switched
power supply.
- Re-measure SNR and ENOB of all channels and document in spec on wiki
- Analyze noise sources (spikes) on all channels
- Consider moving all channels on the PCB design and having the
Trigger input closest to the DC/DC
- Consider better shielding/decoupling of the DC/DC converterV6.0Erik van der BijErik van der Bijhttps://ohwr.org/project/fmc-adc-100m14b4cha-hw/issues/38V2 - Clean "No ERC" in schematics2019-02-12T11:14:49ZProjectsV2 - Clean "No ERC" in schematicsThere is lots of "No ERC" red cross on pins that are actually used.https://ohwr.org/project/fmc-adc-100m14b4cha-hw/issues/52Temperature sensor not near hottest spot on board2019-02-12T11:14:59ZErik van der BijTemperature sensor not near hottest spot on boardThe temperature sensor IC (IC13) seems to be at a rather cool place on
the board. Consider moving it nearer the components dissipating the most
(DC/DC and drop-down regulator).Maciej FimiarzMaciej Fimiarzhttps://ohwr.org/project/fmc-adc-100m14b4cha-hw/issues/1V5 - Obsolete inductor L1: CTX10-1A-R2019-08-05T11:20:36ZErik van der BijV5 - Obsolete inductor L1: CTX10-1A-RProducer of cards mentioned that the inductor L1, CTX10-1A-R is
obsolete.
This is a transformer used to generate the negative supply voltages.
For the 2018 production the supplier managed to buy the component via a
broker.https://ohwr.org/project/fmc-adc-100m14b4cha-hw/issues/6V5 - T1,T2, BOM description is wrong2019-11-08T18:40:17ZErik van der BijV5 - T1,T2, BOM description is wrongThe BOM at
https://edms.cern.ch/ui/file/1165461/1/EDA-02063-V5-0_pcb-mat.pdf
reads:
T1,T2 2 **50V 200mA** N-Channel Enhancement Mode Field-Effect Transistor
BSH103 NXP SEMICONDUCTORS BSH103 SOT23-3
The description of **50V 200mA** is wrong.
The datasheet at
https://assets.nexperia.com/documents/data-sheet/BSH103.pdf (This NXP
part is moved to Nexperia)
shows **30V 0.85A**.
- Correct description of library item BSH103 to show 30V 0.85A instead
of 50V, 200mA.
- Change NXP SEMICONDUCTORS to Nexperia (see cover letter on the
datasheet)
*Problem found by Seven Solutions, during price enquiry for production.*V6.0Erik van der BijErik van der Bijhttps://ohwr.org/project/fmc-adc-100m14b4cha-hw/issues/32V2 - Oscillations on DAC_n_offset2019-02-12T11:14:45ZProjectsV2 - Oscillations on DAC_n_offsetDC offset correction circuit is oscillating.
Adding a 4.7uF ceramic capacitor between DAC\_n\_offset and GND stops
the oscillations.
\=\> Frequency response linearity must be checked before validation of
this fix\!https://ohwr.org/project/fmc-adc-100m14b4cha-hw/issues/34V2 - Use BSH103 MOSFET for LED drive ?2019-02-12T11:14:46ZProjectsV2 - Use BSH103 MOSFET for LED drive ?The BSH103 is already used for example in the SPEC board.https://ohwr.org/project/fmc-adc-100m14b4cha-hw/issues/37V2 - PRSNT_M2C_L comment is on the wrong pin of the FMC connector2019-02-12T11:14:48ZProjectsV2 - PRSNT_M2C_L comment is on the wrong pin of the FMC connectorIn "SAMTEC connector.SchDoc", the comment on pin h1 of J6H connector
says "PRSNT\_M2C\_L".
But referring to the VITA FMC standard the h1 pin is "VREF\_A\_M2C".
This is a minor issue as this pin is not connected in the design.https://ohwr.org/project/fmc-adc-100m14b4cha-hw/issues/41V2 - C44 is too close to the edge2019-02-12T11:14:51ZProjectsV2 - C44 is too close to the edgeC44 is too close to the board edge.
Has already been pulled out on one board.
C2 is also quite close to the edge.https://ohwr.org/project/fmc-adc-100m14b4cha-hw/issues/23V3 - Add Disconnect input option on schematics2019-02-12T11:14:38ZProjectsV3 - Add Disconnect input option on schematicsOn the last schematics page (pin assignment) add:
Disconnect input: SW1, SW4, SW5, SW6 = OFFErik van der BijErik van der Bijhttps://ohwr.org/project/fmc-adc-100m14b4cha-hw/issues/35V2 - Connect ALERT pin of MCP9801-M/MS to the FMC connector2019-02-12T11:14:47ZProjectsV2 - Connect ALERT pin of MCP9801-M/MS to the FMC connectorThe ALERT pin of MCP9801-M/MS must be connected to the FMC connector.
This is to generate the mezzanine over-heat interrupt.https://ohwr.org/project/fmc-adc-100m14b4cha-hw/issues/40V2 - solder mask cutout badly placed2019-02-12T11:14:50ZProjectsV2 - solder mask cutout badly placedThe solder mask cutout under IC9 is badly placed.https://ohwr.org/project/fmc-adc-100m14b4cha-hw/issues/5856 Ohm resistor in 1812 package not easily available2019-02-12T11:15:03ZErik van der Bij56 Ohm resistor in 1812 package not easily availableThe 56 Ohm resistor in 1812 package (used for the External trigger
input) is not easily available. Replace by 50 Ohm type.https://ohwr.org/project/fmc-adc-100m14b4cha-hw/issues/19V4 - 6V supply is too high2019-02-12T11:14:35ZErik van der BijV4 - 6V supply is too highFeedback from INCAA.
\+6 Volt is not 6.0 Volt. Vout = 10 uA \* 620k = 6.2 Volt typical.
The 10 uA current in the formula above can be 10.1 uA, then Vout = 10.1
uA \* (620k + 1%) = 6.3 Volt.
This results in a 5.5 Volt of 6.3 - 0.6 = 5.7 Volt, which is above the
maximum voltage of the offset DAC’s.https://ohwr.org/project/fmc-adc-100m14b4cha-hw/issues/20V4 - Thermal relief pads of LEMO connectors too large2019-02-12T11:14:36ZErik van der BijV4 - Thermal relief pads of LEMO connectors too largeFeedback from INCAA:
Thermal relief pads J1-J5, pad spoke width on all 3 layers are 4 \* 0.4
mm. This is not recommended for (wave-)solder process (IPC2221 &
IPC2222).
PAD diameter is 1.6 mm. thermal spoke width = (PAD diameter \* 60 %) /
\# spokes = 1,6 \* 0.6 / 12 = 0.08 mm per spoke or less spokes.https://ohwr.org/project/fmc-adc-100m14b4cha-hw/issues/36V2 - Check all comment in the schematics2019-02-12T11:14:48ZProjectsV2 - Check all comment in the schematicsFew comments are not very clear.https://ohwr.org/project/fmc-adc-100m14b4cha-hw/issues/39V2 - Mistake in schematic comment page ADC.SchDoc2019-02-12T11:14:49ZProjectsV2 - Mistake in schematic comment page ADC.SchDocIt is written:
\_For normal use, don't mount C24 and C25.
For testing purpose remove C24 and C25 and
solder C22 and C23. Clock needs to be
delivered via not dedicated LA01 pair.\_
It should be replaced by:
\_For normal use, don't mount C24 and C25.
For testing purpose remove C22 and C23 and
solder C24 and C25. Clock needs to be
delivered via CLK2\_BIDIR pair (HPC only).\_Erik van der BijErik van der Bijhttps://ohwr.org/project/fmc-adc-100m14b4cha-hw/issues/43V2: capacitors selecting clock to use are all mounted2019-02-12T11:14:52ZErik van der BijV2: capacitors selecting clock to use are all mountedIn the first production of 10 cards of the V2 version of the card, the
capacitors that select the clock input are all mounted, shorting several
clock inputs.
Verify if the schematics or production documentation is wrong.
\- signaled by Tom.