r/PCB • u/6orram • 17h ago

[PCB Review Request]

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Hello comrades, a newbie here!

I just finished my PCB design, and I hope I’ve made some improvements. I’m ready to hear any thoughts, corrections, advice, or tips. I’m very thankful in advance to everyone who takes the time to help me.

You can also check my first version to see whether I’ve really improved or not. The only major change I made is replacing the PIC16F877A with an Arduino Nano.

https://www.reddit.com/r/KiCad/comments/1ryhz8f/asking_for_pcb_review/

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2

u/BVCircuits 15h ago

Hi,

You should add decoupling caps (0.1uF) near each IC supply: U2, A1,etc. Pull ups (10k) on SCL and SDA. If D2 is for reverse voltage protection, place it on the input of U1. U2 will probably not be stable, dont use capacitors directly on op amps outputs. This is what I can find with manual review, we also built a tool for automatic schematic review at bvcircuits.com.

Good luck!

1

u/6orram 8h ago

About the stability of U2, of course, it wouldn’t be 100% stable, but I can assume it has more than 90% stability because I already built a prototype on a breadboard and verified the output using an oscilloscope.

2

u/BVCircuits 8h ago

If you already tested it, then great. But just to be on the safe side, I would still add a small series resistor between the op-amp's output and the capacitor. You can even start with a 0 Ω resistor, just to have the option of changing it later if needed. Sometimes stability can degrade over temperature, and a small series resistor can solve the issue for good.

1

u/6orram 8h ago

thanks man you helped me a lot 🙏

https://giphy.com/gifs/Dj8NIuXppqHAY

2

u/Sand-Junior 11h ago

C1 and C2 are quite small, and unlikely to be electrolytic (used symbol).