DesignReview21102011
21/11/2011
200ksps 16 bit ADC FMC
Present: R.Millar, M.Cattin, T.Wlostwski, E.van der Bij
General
- Fill in name of the designer and the date of drawing for all pages.
- Done
- All unconnected pins should be marked as No DRC (with a cross).
- Open Hardware text should be added to all pages of the schematic
- to be added before submission to drawing office
Page 1
- Connector headers should be ordered in the same way as other FMC
designs.
- Done
- Connector heads should be labled with a text string.
- Done
- Notes should be added to give clarity on how the camera link cable.
- to be added before submission to drawing office
Page 2
- i2C driven DAC (IC2) should be replaced with an SPI DAC (85662), in
order to be similar to other FMC designs.
- Done
- All components should be powered by 3.3V rather than a combination
of 3.3V and 2.5V.
- Flipflop (IC4) has been left at 2.5 V due to the fact that vdrive for the ADC is 2.5
- This means that the thevenin termination shall use 2.5V as well
- Remove "Flip Flop" text, and alter "Single ended to LVDS" text.
- Done
- Remove comments which were added for the purpose of the design
review.
- Done
- Remove series termination on "CONVST" line, replace with thevenin
termination at the ADC end (convst line page 3).
- Done
Page 3
- Replace 1k resistors on ADC input with a higher resistance, in order
to limit the current to 10mA should the voltage exceed 16.5 V.
- Done, replaced with 2k2 resistors
- Add ADR421 2.5V voltage reference, and input to the refin/refout net
on the ADC chips.
- Done
- Allow 'Ref_select' to be programable, in order that the user can
select between the ADR421 as a reference, and alternatively use one
of the ADCs bandgap reference for both chips.
- Initially this was left in such manner that if the ADR421 could be left unmounted, and the internal bandgap reference could be output on this line, to provide a reference for a second chip.
- However, since the review the ADR421 has been used to provide a reference voltage fot the DAC on the board, for the prototype board.
- This should be ok for the prototype however perhaps this should be altered before being submitted to the design office. Requires further discussion
Page 4
- Replace BSR17A BJTs with MOSFETS.
- OK
- Ensure 10uF capacitors are 1206.
- OK