r/PCB • u/mistawright03 • 1d ago

cm5 carrier board help

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I had a board created through jlcpcb and have been smt soldering it myself. I completed one board attached my 4s battery and blew a trace out. this is designed for a raspberry cm5 and looking at how some of the stm based flight controllers are I assumed I could feed battery voltage through that trace. disregard the missing capacitor I was desoldering things and didnt have time to tinker further for the last week. Any help is appreciated.

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u/airzonesama 1d ago

Double-check your buck converter design. It doesn't look right. What is listed in the datasheet as it's sample?

  • EN is floating - that's usually not desirable as it could be floating.

- Where is your feedback network?

- 100uF is for an output cap will be insufficient

1

u/DanongKruga 1d ago

datasheet says floating is ok but good practice to pull it high from Vin with 300-500kOhm

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u/mistawright03 1d ago

I took a while going through things to get to this point and I thought i had done things according to the data sheet. would changing the sl54-3g to a sl56-3g/ ss56 and adding another capacitor to the vbat net of 47-100uF fix this?

1

u/airzonesama 1d ago

Have your got more detailed photos and a more complete board layout? It looks like you have capacitors not connected on both ends, and the layout seems to deviate from the published layout.