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The only problem with this chip, is that the switching frequency is fixed, that may cause some problems when selecting Inductors, luckily, after calculation I can source pretty good inductors based on the fixed frequency, so in the end I chose the MP2491CGQB-Z chip
EN Current Calculation:
R_Pullup +3kOhm (internal pullup) = (24V-7V)/I_EN (7Volt is the internal Zener Diode)
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In this case, R_Pullup=220kR, so I_EN=62.7uA, smaller than the 100uA, which is good.
Inductor
From the data sheet the design requirements of the inductors is that:
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Updated Placements (From 9-30 to 10-2)
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Routing
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PDN Analysis
Goal is to calculate loop impedance for the following:
VBUS: Input connector -> NMOS, NMOS -> Buck IC
SW: Buck IC -> Inductor
5V: Inductor -> Pixhawk Conn, Inductor -> USB-C Conn, also do Inductor to farthest decoupling cap down (basically before the via punch down to L4).
Used the Power Analyzer by Keysight tool, not able to calculate the loop impedance directly, use the voltage drop and current simulated to calculated loop impedance.
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Pixhawk Wiring
The Pixhawk connector that I find is the 5024430670 Molex Clickmate connector, linked below:
https://www.digikey.ca/en/products/detail/molex/5024430670/2380429
The link below is the pixhawk wiring standard
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The wiring harness that WARG use is 1:1 harness, as pictured, the red cable indicating pin 1
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Comparing the cable with the pin placements on my PCB shows that it is correct
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