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# Review02032010 improvements
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This page shows the replies to the [Review02032010](Review02032010) and
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the improvements made.
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# Detailed comments on schematics
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## Sheet 1: High Pin Count Connector
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- LA00\_CC\_P should be called LA00\_P\_CC (same for N). Change also
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where this signal is used.
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- *Names corrected on both places.*
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- VIO\_B\_M2C is not used: remove signal.
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- *Done.*
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- Remove all signals that are not used in the design to prevent
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confusion.
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- Mark the meaning of B1-B4 and FIG1-FIG6.
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- Mark LA23\_N/P to be a differential pair.
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- Check if LA06\_P/N are correct (pair, both signals used?).
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## Sheet 2: Input stage
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- Sheets 3, 4 and 5 should be the same. This has not been verified.
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Make sure all modifications are done on all channels.
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- Consider inserting an inductor at the negative input to make it
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symmetrical to the positive input (verify AA's mail about this).
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- Add a note on the input ranges, voltage ranges at critical points in
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the schematic. This should also make clear that it's an input range
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of 10V (Vpp) with a programmable offset between -5V and +5V.
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Possibly give examples of usage to clarify.
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- If 50 Ohm setting: +/-7.5V maximum.
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- Add names SW1-SW7 in schematic (refer to sheet 11).
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## Sheet 6: Linear Technologies' ADC
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- Add a note about the different frequencies of DCO, FR, ENC.
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- Add 2 resistors to select the sensitivity of the ADC (SENSE): 100
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Ohm to Vdd, 100 K placeholder to Gnd (normally not mount).
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- symbol misses overline on CS.
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## Sheet 7: DACs and Vref source
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- Add comments on ranges of signals.
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- Add 100nF on +12V\_filtered of ADR445 (IC2).
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- Add 100nF on supply of ADA4004 (IC5 DAC buffers).
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- Check if the ADC can give out a status on the SDO pins. If so,
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connect it to the FMC connector.
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- Use the B version of the reference voltage generator ADR445ARMZ.
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These have a better temperature stability (verify and verify price
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difference).
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- **EP (external pad) of the OPAMP should be connected to the negative
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supply voltage instead of the Gnd. Check with datasheet.**
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- **The DACs are supplied with +6V while this is the absolute maximum
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voltage. Check if they should be supplied with a lower voltage and
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how it should be generated.**
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## Sheet 8: I2C memory and LED indicator
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- **Redo the trigger input stage so that it can withstand a +/-10V
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input signal as users can by mistake connect an input signal to this
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connector.**
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- R117 56 Ohm trigger input termination resistor: use a 0.5 Watt type.
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- Verify dissipation capability of R116.
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- Change LEDs into green types.
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- Add texts to LEDs: Trig'd, OK.
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- Add thermometer IC. This can ultimately be used to add a temperature
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compensation. The same chip should also provide a unique serial ID.
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- Verify if the memory is large enough to store all calibration
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parameters.
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- Put the value of R118/R119 next to component.
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- Document input levels and trigger level.
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## Sheet 9: Power supplies
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- Add 10pF C to SET input of LT3080.
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- Replace 60K4 SET resistor by 600K to have correct 6V output.
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- Replace C46 1uF by at least 2.2uF.
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- Symbols shutdown pins of IC9 and IC10 are not marked with active low
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marker.
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- **IC8 LT3080, pin EP should be connected to Vout and not to Gnd.
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Check datasheet.**
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- C48 (220pF on LT1931 output) should have a different value to match
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phase lead zero. Check datasheet.
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## Sheet 10: ADC clock generator
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- Replace symbol by Si570 and re-verify with someone else.
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- Add note on the I2C address.
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# Other comments
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- Make a Bill-of-Material and verify if the number of different
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components can be reduced.
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- Calculate the total component costs.
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- Print out the netlist and verify it by hand to make absolutely sure
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that all signals are connected with the right number of pins.
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- Add the datasheets of all used components in EDMS (Ordering info).
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- Make sure that the capacitors are of the X7R type.
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# Additions to the manual
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- Add a note about the crosstalk: do not put an input with a */-5V
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range next to one with a*/-50mV range.
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- Specify input ranges, maximum voltage with 50 Ohm setting, etc (see
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comments for Sheet 2).
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# PCB layout (preliminary review)
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- Move IC8 12V to 6V drop-down converter to the other side of the FMC
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connector. This way it can be cooled by the stand-off pin (it
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dissipates 0.9 Watt).
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- Consider placing the filter inductors alternatively on the top and
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bottom side to reduce coupling.
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- Pay attention to ENC inputs of ADC: coupling capacitors should be
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very close to have no stubs.
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- **It seems that the LEDs and the connectors are too much advanced
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and will touch the front-panel.**
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- Use solid ground planes.
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- Seriously consider to use power planes instead of using tracks.
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- Verify the switching supply layout.
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\- Maciej Fimiarz - 4 March 2010
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