How does an USB-C charger switches on?

[Beeldbuisje]

A common USB-C charger seems not to give 5V when he's not connecting to an appliance. When connected, it starts with 5V and goes up to the tension needed.

In my case I'm working on a Apple A1707 macbook, with defective CD3215 chips.
On one port that previously worked, my charger doesn't switch on.

But what makes this charger to switch on. Does it has to sense a load, or does it require data on some line, or how...

Seems to be a mystery. Hopefully someone can explain this.

[sam_sam_sam]

Re: How does an USB-C charger switches on?

I am not exactly sure what makes it change what I do know is that it has a ic chip that selects the voltage voltage when it conditions are correct and met

[keeney123]

Re: How does an USB-C charger switches on?

A common USB-C charger seems not to give 5V when he's not connecting to an appliance. When connected, it starts with 5V and goes up to the tension needed.

In my case I'm working on a Apple A1707 macbook, with defective CD3215 chips.
On one port that previously worked, my charger doesn't switch on.

But what makes this charger to switch on. Does it has to sense a load, or does it require data on some line, or how...

Seems to be a mystery. Hopefully someone can explain this.

This might help you

https://logi.wiki/index.php/CD3215_Bootup_Sequence

https://www.ti.com/power-management/...eyMatch=CD3215

and finally the TI data sheet for such a controller:
https://cdn.badcaps-static.com/pdfs/...f818e262c5.pdf

[Beeldbuisje]

Re: How does an USB-C charger switches on?

The problem of the macbook is solved... Not repairable; there're lot of copper paths which becomes loose. Don't know what happened with this board, I've never seen this before.

Anyway, I figured out (thanks for the URL's) the importance of the CC pins. The data on this CC pins are responsible for selecting the output voltage.

But, measuring on VBUS or CC pins with disconnected charger, but charger plugged in in 230V AC, gives... nothing. Nor measured with scope, nor with multimeter.
The USB-C plugged in in a working Macbook let's see data transfer on CC pins.

But how it starts... I still can't find it anywhere.

[keeney123]

Re: How does an USB-C charger switches on?

The problem of the macbook is solved... Not repairable; there're lot of copper paths which becomes loose. Don't know what happened with this board, I've never seen this before.

Anyway, I figured out (thanks for the URL's) the importance of the CC pins. The data on this CC pins are responsible for selecting the output voltage.

But, measuring on VBUS or CC pins with disconnected charger, but charger plugged in in 230V AC, gives... nothing. Nor measured with scope, nor with multimeter.
The USB-C plugged in in a working Macbook let's see data transfer on CC pins.

But how it starts... I still can't find it anywhere.

Your chip I have no idea how that starts as I can not find detailed specs like TI. With the TI TPS65983B, which is the bottom url link I supplied, on page 27 is parameter measurement wave forms and the line of time for UVR_out3V3. All those things have to happen in order to have the chip to work. It then goes on to explain in detailed on page 29 its workings. On page 30 is the internal block diagram. The digital core has Analog to digital convertors. I have not read all the way though this link. However, I would imagine that there are encoders in the output of the Digital Core to the Port Data Multiplexer that combine with the input/output lines of the Port Data Multiplexer to determine what and when something is written on those lines either to the USB-C or back to the computer.