Issues on prototype

  • Resistor wrong on -1V regulator (should be 20k not 2k)
  • Enables not connected to +V on LDO regulators (3.3V, 4V)
  • Missing cap on output of 3.3V LDO
  • ADC "reset" signal wired to incorrect pin on FMC connector
  • Clock must be AC-coupled to ADC (with 100 ohm term upstream)

To Do list

(new items added at top)

  • Move L1 to the front. It is likely to run into the carrier board on the back. OK
  • The input connectors should not be marked "U1" etc but "J1" or "P1" etc OK
  • The silkscreen text still needs some cleaning up, maybe Dan can say something about this. OK
  • On the back, the oscillator is too close to other components IMO


  • Op-amp (THS4509)
    • Footprint, pinout OK
    • Need solder mask opening on center / thermal pad? OK
    • Add pin 1 mark (circle) on silkscreen between pins 1 amd 16 OK
  • ADC chip
    • See adc_traces.jpgOK
      • No traces wider than pads OK
      • No traces between pads and thermal pad OK
      • No traces or any other copper between pads OK
    • Add component body outline on silkscreen OK
    • Add pin 1 / orientation mark on silkscreen OK
    • LVdd is a long skinny trace. Should be wider (25-40 mils) OK
    • Add traces from GND pins to thermal pad. OK
    • Ensure thermal pad is connected to GND, looks like it might be 3V3 now! OK
    • pins CFG1-4 and PDN are configuration pins we're not using and are GND. This is OK, but they should have traces maybe 100-200 mils away from the chip to vias (one shared via is OK) so if we've messed up we can cut the traces and wire them to something else. OK
    • Solder paste layout on ADC thermal pad per data sheet OK-ish
  • U13 and U16 (regulators)
    • Shrink solder paste opening a bit away from other pins (check data sheet) OK
  • U12 (dc/dc dual output)
    • Move TP1 away from part OK
    • Check data sheet for solder mask and solder paste recommendations
      • "SOlder mask defined" (SMD) "Non solder mask defined" (NSMD) pad types | It didn't look like the datasheet said anything so I went with NSMD
    • double check if it's a BGA (with solder) or LGA (no solder) type package | Only available in LGA; LTM8045 (Neg. Converter) available in BGA
  • General
    • make all copper area boundaries on grid and separations all ~ 15 mils OK
    • Add mounting holes in front corners of board OK
    • Route SEN above power connector OK
Last modified 5 years ago Last modified on Jul 19, 2017, 4:26:43 PM