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Design Notes/Justifications

Fan Candidates

https://www.amazon.com/Raspberry-Controllable-Control-Fan%EF%BC%8CRaspberry-40x40x10mm/dp/B0C4PN9BHK?source=ps-sl-shoppingads-lpcontext&ref_=fplfs&psc=1&smid=A5CVPLET1CA6

Best Fan Candidate

4 pins (5V, GND, PWM OUT, TACHO IN)

Claims 250mA max

https://www.amazon.com/Noctua-Cooling-Bearing-NF-A4X10-FLX-5V/dp/B00NEMGCIA/ref=d_pd_pss_dp_d_1_sccl_2_1/131-4794042-8775400?pd_rd_w=N46Zi&content-id=amzn1.sym.3dd6ff5f-e1b5-4c4b-9429-39c9f308776c&pf_rd_p=3dd6ff5f-e1b5-4c4b-9429-39c9f308776c&pf_rd_r=TGEQXVW5BY2A89NEMS3F&pd_rd_wg=fbnX7&pd_rd_r=19140b40-0674-4be5-ab82-24e65d06cee8&pd_rd_i=B00NEMGCIA&th=1

9 Pin Locking Connector

PCB connector

https://www.digikey.com/en/products/detail/molex/2023960907/7785664?s=N4IgjCBcoLQBxVAYygMwIYBsDOBTANCAPZQDaIAnAAxUD8ArgC4C2A%2BtkfQE5K4C81KiAC6AX1GEATGRCSqkgMwUAbFWoB2EaKA&utm_campaign=buynow&utm_medium=supplier

Wire connector

https://www.digikey.com/en/products/detail/molex/5013300900/1531506

• Good stock (20,000+ on each item)

• 9 Pos

• SMT, right angle mounted

• Locking

• Molex

LDO Selection

LDO is rated for 1A minimum and 1.3A typical? The 800mA is the current at which the dropout voltage is measured at, and for that there's a plot on page 8 of the datasheet that shows <1.4V dropout voltage at all temperatures at 1A output, so with a 5V input we should be in the clear. Based on that I'm going to leave the LDOs in, as even the minimum rating clears the absolute maximum of the ESPs

ESPs draw 500mA tops each

We should be in the clear with these 1.3A typical LDOs

Chip Antennas

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Reference Designators

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Mounting Grid

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Board mounting holes are currently 90mm by 60mm which allows it to be mounted on a 30mmx30mm scheme that is standard in WARG. A future board revision may aim to move many components inwards and bring the board edge up to the connectors for aesthetic and board size optimization.

Via Sizing & Stitching

The following app note was referenced for stitching the GND pours around the RF sections: https://www.infineon.com/dgdl/Infineon-AN91445_Antenna_Design_and_RF_Layout_Guidelines-ApplicationNotes-v09_00-EN.pdf?fileId=8ac78c8c7cdc391c017d073e054f6227

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