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Electronics => Beginners => Topic started by: Saimoun on May 17, 2024, 09:55:28 am

Title: Extremely simple USB-C power source
Post by: Saimoun on May 17, 2024, 09:55:28 am
Hi

Is it possible to have a simple USB Type-C port on the host/source side without a USB PD chip? (for example turning on/off Vbus with transistors)
All the port has to do is to transmit power, no data.

Thank you :)
Title: Re: Extremely simple USB-C power source
Post by: Saimoun on May 17, 2024, 10:44:21 am
Would something like the attached circuit work for example?

I understand connecting the CC pins together breaks the standard - but since all USB-C cables only connect one of the two it should work?
Title: Re: Extremely simple USB-C power source
Post by: wasedadoc on May 17, 2024, 11:08:36 am
Why do you want/need to switch the power?  Just wire 5v and 0v to the appropriate pins of the socket?
Title: Re: Extremely simple USB-C power source
Post by: tszaboo on May 17, 2024, 11:50:56 am
You don't have to support power delivery for a Type-C port.
I think for a 5V device the only requirements are to have two pulldown resistors on the CC1/CC2, so if you have a simple "OR" detection on these two lines, you can control a current limited power switch with that. There are dedicated USB power controllers as well.
Title: Re: Extremely simple USB-C power source
Post by: Saimoun on May 18, 2024, 09:18:42 am
Why do you want/need to switch the power?  Just wire 5v and 0v to the appropriate pins of the socket?
If you do that and two hosts are plugged into each other them boom >:D
Turning on the Vbus only when a device is connected is part of the spec :)
Title: Re: Extremely simple USB-C power source
Post by: arrio on August 17, 2024, 09:21:37 am
i think just use two diode can simpily fix the standard.
It is worth noting that PMOS may not entirely "open" if you use 10k pull up resister (3.0A@5V), in this case you may use OR gate instead.
New hands here, sorry if it offends :lol: