Roy Starter Project

[royy-mor]

yippeee!
just schematic done

[IshDeshpa]

poop

[IshDeshpa]

A couple things on this LED:

• This Standard Mouser Components sheet has a bunch of common chips that are used for a bunch of boards we manufacture. This is so that we can batch parts and standardize them so that we don't have to buy different LEDs for different boards. I would suggest replacing it with an LED from here (or just pulling somebody elses schematic and copying down the part number, which is what i do)
• The datasheet for this LED says the forward voltage is 2.9V and the forward current is 20mA. Reference this to recalculate your resistor value so that the LED doesn't blow up (if you continue to use this LED). Additionally, this calculation is usually a lower bound so it's ok if the resistor value is higher than required (but maybe not lower)

[IshDeshpa]

oops nvm you right my bad :)

[royy-mor]

The led symbol is admittedly huge but my led is cheaper and looks better so maybe we should change our standard blue led. Linking the mouser page here for easier review

[IshDeshpa]

Just making sure you've thought about this, not sure if these are actually problems so take it with a grain of salt.

• What voltage is your PWM signal input high at and what is it low at?
• What frequency is your PWM signal running at?
• Will the high value resistor on the gate input affect your switching time? I noticed it's 100k but could you/should you make it 10k or 1k?
• It's good that you have the pulldown before the gate current limiting resistor, not after. That way you don't accidentally make it a voltage divider

[IshDeshpa]

Could you spec out a part for this diode?

[IshDeshpa]

If the BPS board is providing GNDPWR as well as four PWM signals, where is your GND reference coming in for the PWM signals themselves? Additionally, how would the MOSFET work at all if the PWM signal's voltage reference (GND) and the source voltage on the MOSFET (GNDPWR) are different?

[Lakshay983]

Like Ishan said, make sure to fix to only use the GND instead of using GNDPWR.

You also don't need to import other parts for the LED, you should only need to use the generic LED symbol and then edit the part number.

Nitpicky, you don't need to use global labels, I prefer using just regular labels.

irl you need to pick a good flyback diode like Ishan said, but for the sake of this assignment it's not needed.

LGTM other than that

[IshDeshpa]

boo right angle bad

[IshDeshpa]

boo right angle bad

[IshDeshpa]

far too close (this pretty much applies to everything on here)

[IshDeshpa]

u could use a power plane for 12V and GND and that would make a lot of these power traces just go away

[IshDeshpa]

Did you import settings from another project for your DRC, and then run your DRC? It seems like it's not throwing enough violations.

[IshDeshpa]

how is the user of the fan board going to know which connectors are for what? i suggest adding labels.
nitpick but not really.

[IshDeshpa]

You could probably put the resistor underneath the LED here and then do in-pad vias to it. Honestly there's a lot of spots on the board you could make the traces shorter if the pads were laid out differently; e.g. just because things are close together does not mean it's the optimal layout (rather, you want to place pads that connect together relatively closer). Also stuff is probably hella unsolderable and no safety factor in terms of placing components too close

[IshDeshpa]

(where the face is the board and the components are the facial features)

[IshDeshpa]

Points off for no UTSVT and no Hallock