Power supply from USB wall adapter...some works...some doesn't

Thread Starter

atomosrl

Joined Apr 22, 2024
3
Hello!

I've two battery powered board with onboard charger.
Here some detail
  1. Board1 has fast charger (needs 15V from wall adapter) and I've a power delivery IC to request correct voltage from the power supply
  2. Board2 has linear charger (needs 5V), there's not power delivery IC in this case
I can charge batteries of Board1 with all kind of power adapter (QC compliant) I have.
I can charge batteries of Board2 only with some adapter, not all.

Question: in your opinion (and knowledge)...with quick charge adapter I've also to request 5V voltage?

how to recognize an adapter compliant with no power delivery IC board?

Thanks
Stefano
 

Ya’akov

Joined Jan 27, 2019
9,265
Welcome to AAC.

PD compliant chargers should provide 5vSAFE, which is 5V at 500mA, in the absence of any indication of the downstream device requirements. Other chargers may or may not provide 5V unless they see some valid termination of the data lines indicating a power consuming device.

You should measure the output of the non-working chargers and see if they default to no output. If that's the case, you should terminate the data lines on the side of your board using one of the standards which those chargers support.

Trying shorting D+ and D- (or otherwise bridging them with ≤200Ω).
 

Thread Starter

atomosrl

Joined Apr 22, 2024
3
1 For Board1 with the fast charger and PD IC, you can use a QC-compliant adapter, and the PD IC will handle the voltage negotiation.
2 For Board2 with the linear charger and no PD IC, you need to use a 5V power adapter that directly provides the required voltage for the linear charger.
Thank you Lilly

Welcome to AAC.

PD compliant chargers should provide 5vSAFE, which is 5V at 500mA, in the absence of any indication of the downstream device requirements. Other chargers may or may not provide 5V unless they see some valid termination of the data lines indicating a power consuming device.

You should measure the output of the non-working chargers and see if they default to no output. If that's the case, you should terminate the data lines on the side of your board using one of the standards which those chargers support.

Trying shorting D+ and D- (or otherwise bridging them with ≤200Ω).
I agree with you Ya'akov. I've also to test connectors. At this level of investigation may be I've a fake contact (connector on Board1 has not the same p/n of Board2

Thank you
Stefano
 
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