Hello All,

I am considering switching from USB-A to USB-C on my project, but I am a bit confused on how to get the 5v voltage I want.

I would like to just use a USB-C 2 leads power cable. As far as can read the way to get 5v is to pull CC1 and CC2 to ground. But there would be no way of doing that with a 2 lead cable. Does such a cable already have resistors build in? Or will the power adapter determine what to supply?

Hopefully someone can shed some light. All input much appreciated.

Best,
Olav

 

depends on if it's really USB-c you may get no power at all

 

Hello All,

I am considering switching from USB-A to USB-C on my project, but I am a bit confused on how to get the 5v voltage I want.

I would like to just use a USB-C 2 leads power cable. As far as can read the way to get 5v is to pull CC1 and CC2 to ground. But there would be no way of doing that with a 2 lead cable. Does such a cable already have resistors build in? Or will the power adapter determine what to supply?

Hopefully someone can shed some light. All input much appreciated.

Best,
Olav

As the previous post noted, with some of the newer wall warts you do not get any voltage until the device being powered requests a certain voltage level, and then possibly requests a higher voltage level after that.
It's gotten more complicated as time goes on.
Some devices will not even power up on some wall warts because they can't communicate with the wall wart. It's nuts.

In this case and others, you have to get what is referred to as a "trigger". That is a device you plug in first so you can set the output voltage. The trigger tells the wall wart to put out whatever voltage you set the trigger to. You have to be careful though because if you set the trigger to 12 volts and go to power a 5 volt device, it will most likely either blow out the device entirely or just blow out the charging circuit inside the device.

 

https://www.amazon.com/sspa/click?ie=UTF8&spc=MTo3NjU1OTg3MjQ2NDM0NjU6MTcyNzgxNTQ3NDpzcF9hdGY6MzAwMzQ1NjIxOTgyNDAyOjowOjo&url=/Trigger-Adjustable-Voltage-Module-Male/dp/B0D33LHHK1/ref=sr_1_1_sspa?crid=1RLI5DDJ8VFI6&dib=eyJ2IjoiMSJ9.hlT06r3bRztCpALgxHZGJXuW5APjViOd_vyVTJEQNBqtaFlxTQbT4FuV8P6WThml8gUYkgsBDjVMWev9NWoL-5VW9fviuYajGOew4mMh6ahL0unyIuRRQAJ9Gn_uUOIHGsuilE5nZoHPI-8hdPYAroDul0rOH6JET6HqGMzOpjwZi8pKKkXk__dxbcS57rLccAGY2F_NRO0IiRZW4Q4Ob3oui8p9cahS5Hggd4XGLFk.YfaPyylrESHlJVTEO1KQlh-tFVFQUAyrWlPN4ZkHkhs&dib_tag=se&keywords=usb+c+pd+board&qid=1727815474&sprefix=usb+c+pd+%2Caps%2C137&sr=8-1-spons&sp_csd=d2lkZ2V0TmFtZT1zcF9hdGY&psc=1

If you look around you maybe find one with USB C male to female

Lots of stuff using USB C pd you add the pd chip to your board it then tell the USB C port that you need 5 volts or up to 24 volts some will do 3.3 ,5 ,6 ,9,12, 15 , 24
But you get into more problems some will not let data threw only power and some will do power and data
The USB-C pd on my laptop will put out 5 and let me use a cord to my arduino with USB-C to USB-C but it can put out more if a pd trigger ask for higher voltage

My iphone uses USB-C it will fast charge but finding right USB C cord not all will work some you get no power at all

 

Hey All,

Thank you for all the input.

So just to clarify, it sounds to me that a two lead usb-c cable is pretty useless. Basically the way to go would be to have an IC on the board for negotiating the power and to use a cable with more leads to be able to control the necessary pins?

I will be supplying a USB-C adapter with my product so I suppose I could just choose one I know will output even without negotiation. But I guess that would be risky if for some reason an adapter would somehow decide to output more than 5v?

Best,
Olav

 

To make USB -C work you have to set your board up for it. Its not that hard to do.

Extracting Power From USB Type C | Hackaday

 

Hey All,

Thank you for all the input.

So just to clarify, it sounds to me that a two lead usb-c cable is pretty useless. Basically the way to go would be to have an IC on the board for negotiating the power and to use a cable with more leads to be able to control the necessary pins?

I will be supplying a USB-C adapter with my product so I suppose I could just choose one I know will output even without negotiation. But I guess that would be risky if for some reason an adapter would somehow decide to output more than 5v?

Best,
Olav

It's not useless but it would only deliver 5v at maybe 300ma or something if you have a less modern 5v, 1 amp wall wart.

I forgot to mention another thing though. Regardless what kind of wall wart you get you also have to get a cable that can support the full power that you are expecting. Many run of the mill USB cables will only deliver so much current and that's it.
For example, I have a 45 watt wall wart that can deliver 24 watts to my phone, but because I've had so many phone batteries fatten up over time with high current charging, I decided to start charging at a much lower rate. In fact, 3 to 5 watts. I can get this by just using a cable that does not work as well as a full power cable. Instead of 12v at 2 amps or something, this keeps it at 5v at 650ma, which is much easier on the life of the internal, non-replaceable battery.
At least 3 or 4 batteries from previous phones had swelled up over a period of maybe 2 years, and I figure that was because they were being charged at the higher rates like 9v at 2 amps or 12v at 2 amps or something like that. So now I am limiting the current, and also limiting the max charge voltage to 85 percent via the phone software. I am hoping this allows the batteries to last at least 3 years that should be enough I think.

Anyway, cables that can handle more power are usually rated like that. For example, 60 watts, 100 watts, 240 watts. If you need the higher power then you have to get a good cable with an actual power rating.

 

Hey,

Thank you for the additional input - I'm learning a lot here!

Just for completeness for my product I will need around 1 - 1.5a at 5v.

Best,
Olav

 

Hey,

Thank you for the additional input - I'm learning a lot here!

Just for completeness for my product I will need around 1 - 1.5a at 5v.

Best,
Olav

Welcome to AAC.

If you are going to incorporate Type-C connectors you really need to actually support USB PD protocol and provide OVP.

There are quite a few “chargers“ that have Type-C connectors on them buy only and always provide 9V or 12V. If your product features a jack that can lead to its turning to smoke it warranty support is going to be problematic.

Fortunately, this isn‘t really that hard to do. The CH422K chip is a cheap and readily available general purpose solution. Check out the datasheet. The chip has impressive capabilities and it will ensure your product doesn’t just have Type-C connectors but actually supports PD (and other fast charge protocols if that ever becomes relevant).

 

The cables are not a simple pick you have to know what your getting they sale cheap ones for the real thing and some will not work I have 2 pd chargers but only haft of the
usb C cords work with them.
I think they little more smart cause they only output five volts unless your device calls for more they both go up to 24 volts and say there 3 amps but I use them to power arduino
and I only get 5 volts I'm going to test these more when i get time I run them threw a usb tester that shows the output of volts and amps

 

The cables are not a simple pick you have to know what your getting they sale cheap ones for the real thing and some will not work I have 2 pd chargers but only haft of the
usb C cords work with them.
I think they little more smart cause they only output five volts unless your device calls for more they both go up to 24 volts and say there 3 amps but I use them to power arduino
and I only get 5 volts I'm going to test these more when i get time I run them threw a usb tester that shows the output of volts and amps

The PD standard requires the charger to output either 0V or Vsafe5V which is the name of the default output in the document. The current limits vary with the connection type:

2.0 500mA
3.x 900mA
Type-C 3A

Are all PD labeled devices compliant? Probably not—but I haven’t personally seen a device marked “USB PD” that wasn’t. Note that the Type-C connector is not the same as PD, though it is required for PD compliance.

 

I have actually three of them they they put out five volts with a good cord but like I said some cords don’t work you get nothing

 

Hey,

Thank you for the additional input - I'm learning a lot here!

Just for completeness for my product I will need around 1 - 1.5a at 5v.

Best,
Olav

Hello again,

Oh in that case I have to recommend a regular wall wart that can do 5v at 2 amps. They are widely available.

I've delt with a lot of wall warts for charging because I wanted to get familiar with the different capabilities first hand. The older ones that can put out 5v at 2 amps or 5v at 3 amps generally put out 5v all of the time, and the device draws whatever current it needs be it 500ma, 1amp, 2amps, etc.

I've even explored some of the wireless chargers and they vary also. They are also usually rated in terms of power also.

One of the biggest variations I have found is with the multiple output wall warts made for charging. They might claim that they can do 100 watts, but that is usually the total for all of the ports. That means that if it has four ports each one may only go up to a max of 25 watts, but they can split it in various ways including what is being drawn from each port simultaneously. One port may be able to do 50 watts and three 25 watts, but that 50 watts is only if one of the other three is not being used, for example. The variation is so wide here that you have to read the specs very, very carefully before you buy.

 

I have actually three of them they they put out five volts with a good cord but like I said some cords don’t work you get nothing

Type-C cables have a big rôle in PD negotiation. Two of the pins in the Type-C connector are used to provide information to both the source (supply) and the sink (load). These are CC1 (A5) and CC2 (B5) as you can see in the graphic.

​

Because the connector is reversible, the pins are mirrored—the A row starting with GND and then TX1+ and the B row end8ng with GND preceded by TX2+. The CC (Configuration Channel) pins are CC1 and CC2 because of the rows each appears in.

The first thing the CC pins do is determine how the cable is plugged in. This is because there are resistors on the CC pins that can be used to work out which of the two pins is electrically active, among other things

Type	Value	Device	Function
Pull-up	56kΩ	Source	Advertises 1.5A current at 5V
Pull-up	22kΩ	Source	Advertises 3A current at 5V
Pull-up	10kΩ	Source	Advertises default USB current (500mA/900mA depending on USB version)
Pull-down	5.1kΩ	Sink	Indicates sink, detects current and cable orientation
Pull-down	1kΩ¹	Sink	Indicates passive cable; used to limit power without negotiation
Pull-down	1kΩ¹	Cable	Indicates passive cable without eMarker²

1. Called Ra in the PD standard, used to indicate a passive cable.
2. eMarkers are active devices that provide capability information to a source.

Once the cable orientation determined, if the cable has an eMarker, it is used by the source to set current limits. If there are no (or improper) pull-downs in the cable, and no eMarker, the source may choose to shut down output for safety not even providing the Vsafe5V.

If the eMarker is valid, the sink can negotiate a voltage and current with the source using data on the active CC pin. This can be a dynamic exchange with several modes. Among them are fixed supply where the sink asks the source for a particular voltage and current from among the standard values advertised by the source; and PPS (Programmable Power Supply) mode where the sink can specify the current and select a voltage somewhere between 3.3 and 24V in 20mV increments. The former is the most common and is useful for devices with simple power needs; the latter is good for sophisticated charging.

So, if a cable lacks pull-downs or an eMarker, some supplies will just shut down the output to be on the safe side.

 

Type-C cables have a big rôle in PD negotiation. Two of the pins in the Type-C connector are used to provide information to both the source (supply) and the sink (load). These are CC1 (A5) and CC2 (B5) as you can see in the graphic.

View attachment 332886
​

Because the connector is reversible, the pins are mirrored—the A row starting with GND and then TX1+ and the B row end8ng with GND preceded by TX2+. The CC (Configuration Channel) pins are CC1 and CC2 because of the rows each appears in.

The first thing the CC pins do is determine how the cable is plugged in. This is because there are resistors on the CC pins that can be used to work out which of the two pins is electrically active, among other things

Type	Value	Device	Function
Pull-up	56kΩ	Source	Advertises 1.5A current at 5V
Pull-up	22kΩ	Source	Advertises 3A current at 5V
Pull-up	10kΩ	Source	Advertises default USB current (500mA/900mA depending on USB version)
Pull-down	5.1kΩ	Sink	Indicates sink, detects current and cable orientation
Pull-down	1kΩ¹	Sink	Indicates passive cable; used to limit power without negotiation
Pull-down	1kΩ¹	Cable	Indicates passive cable without eMarker²

1. Called Ra in the PD standard, used to indicate a passive cable.
2. eMarkers are active devices that provide capability information to a source.

Once the cable orientation determined, if the cable has an eMarker, it is used by the source to set current limits. If there are no (or improper) pull-downs in the cable, and no eMarker, the source may choose to shut down output for safety not even providing the Vsafe5V.

If the eMarker is valid, the sink can negotiate a voltage and current with the source using data on the active CC pin. This can be a dynamic exchange with several modes. Among them are fixed supply where the sink asks the source for a particular voltage and current from among the standard values advertised by the source; and PPS (Programmable Power Supply) mode where the sink can specify the current and select a voltage somewhere between 3.3 and 24V in 20mV increments. The former is the most common and is useful for devices with simple power needs; the latter is good for sophisticated charging.

So, if a cable lacks pull-downs or an eMarker, some supplies will just shut down the output to be on the safe side.

Hi,

Yeah it's gotten so complicated and keeps getting more and more complicated that eventually nothing will work right

What puzzles me is why didn't they do that with hard drives when they went from the EIDE to SATA interface. They complained that the cable for EIDE was too wide and hard to run, yet here we see multiple wires with seeming no limit in sight. EIDE only carries signals too not power, so it should be even simpler. Sata is supposed to be fast, but it's only fast for single operations. EIDE did not seem to have that problem. If we look at the transfer rates for Sata we see widely different speeds for different types of transfers, and only the larger files transfer what we could call fast. In that case it is very fast, but when we have a huge number of small files it could takes hours, literally, as opposed to a few minutes for larger files with the same total byte count. This has plagued me for years now since I have to deal with a LOT of small files on a fairly regular basis. Making new backups could take two or three days. Never had this problem with EIDE drives.
Maybe one day they will go back to a lot of wires in the Sata cable. For now they tackled this problem by going to the newer M2 NVMe drives, which are fairly fast, but still in need of improvement for transfers of a lot of smaller files. Some of these are incredibly fast for larger files though.

I am wondering how far they are going to take this USB C thing. Will we be able to plug in our 1200 watt microwave oven into our cell phones one day?
Oh yeah, and now there is also power delivery upstream also where you can charge one cell phone with another cell phone.
No end to it

 

I reuse cables ive only cut open one USB c one that had more then 4 wires