PCB Review Request Pt 2 Changes

[davidak16]

Hi Again,

So I spread the pages out so they were easier to read at the behest of some kind viewers. Sorry for lack of net labels, I had to put it together on the fly to change sheets and get it out. I've also attached the datasheets for reference.

It would mean the world to me if someone could kindly review and let me know what changes need to be made, would be much appreciated. Thanks in advance for your time.

From my previous post:

I've made it to my 3rd schematic and board design. Please help me understand what I can improve and what mistakes I might be making.

For reference, I'm using BGAs because they're the only feasible package for my application use case. Please let me know if you have any useful routing tips or videos. I'm having trouble finding any visual references for Kicad with fine (.4pitch) BGAs.

I've attached the schematic. I pretty much just followed the data sheet reference designs.

Relevant parts Quick rundown:
- nRF5340
- 2x MAX30009
- ST1AFEBX AFE
- MAX20335 PMIC + MAX17262 fuel gauge


Main concerns:
- Dual MAX30009 topology
- Power rail separation for sensitive analog front ends alongside a BLE radio
- nRF5340 reference design: anything commonly missed?
- ESD/filtering on the electrode inputs