[BOM] Reducing Bill-Of-Materials
To be seen when all other fixes are applied, some ideas below:
- C131 is the only 15pF capacitor, R122 is the only 10Ohm resistor, can we re-use any other already existing value in this design? Or remove the RC filter (see note in fpga-supply-3 section).
- C24 is the only 10pF capacitor, it's value is not critical, please change to another, already existing value in the design
- C240 is the only 100pF capacitor, is it required? datasheet of Si53312 mentions only 1uF bypass capacitor for VDD, VDDOA, VDDOB.
- C276, C290: change to 1uF 0603 X7R; X7R is required by datasheet, and there are plenty of 1uF 0603 used already in the design
- C280, C285, C286, C288, C305, C308, C311, C314, C317, C383: replace those 2.2uF 0402 capacitors with 0603 (like C287). Anyway, some of those 0402 (max 6.3V) are currently used to decouple 5V, so it's better to replace them with 0603
- C15, C17, C132, C134, C297 replace those 22uF 0805 caps with 0603
- C296 replace this 22uF 0805 cap with 1206 (as those are already present in the design)
- C319, C441 replace these 220nF 0603 with 0402 (as there are already 0402 220nF in the design).
- LD6 should be the same part as LD3/LD4
- can we make all 0R resistors of the same size - currently it's a combination of 0603 and 0201?
- R222: 100 Ohm 1% is enough, no need to use 0.1% (see ZCU102 or ZCU106 dev kits)
- R154, R155: these are the only 470Ohm resistors in the design, use another, already existing value as those are only current limiters to IC1.
- R176 doesn't need to be 0.1%, it is also the only resistor of 8k06Ohm. Please replace it with another, already existing value.
- R203 is the only 75k resistor, replace it with another, already used value.
- R212: it's the only 220k value in the design, can be replaced with a combination of 210k + 10k (already used values).
- R220, R221, R233: these are simple pull-ups, use another value from those that are already used in the design.
- R223, R224 are used for 2:1 scaling in feedback loop, these are also the only 249Ohm resistors in the design. Can we use different values, from those already used in the design?
- R254, R255, R258, R259 are I2C pull-ups and the only 2k2 resistors in the design, can we replace them e.g. with 2k87 that are already used in other places?
- R41 is the only 1M resistor, could be replaced with 1M1