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?? the 'negotiation' is usually related to the CURRENT the port can deliver - not the voltage. Where do you get this information from?
what are you on about?
it negotiates voltage, current will be the maximum the cable can supply and the ic charger will pull.....
Actually: both. My smartphone charger goes up to 9 V, too. Plus 1.2 A. Both are above the USB standard.
This is done to increase power delivered over thin cables by less current.
There are proprietary methods (as probably in my phone) and also standardized methods via USB power delivery.
No. More likely a dead phone. When inserted first the phone expects 5 V on the USB port. Only after negotiation with the power supply (charger) will it turn on the necessary circuitry to charge from 9 V. If you supply 9 V without prior negotiation, you risk damaging your phone.
I'm obviously behind the times on this subject - apologies - my understanding is still base don the old versions of USB1/2 where current (power) negotiation referenced 100mA or 500mA after negotiation as per this:
(my bold)
You won't be surprised to know I don't own any USB3 devices!
yes I do risk...
hence the question.... that said! the same 5v rail and 9v rail is shared, that would imply the step down regulator is happy to take up to 9v, the phone charger ic should regulate current and step it down
hence the question, I have seen a dynamo from china which allows you to set the usb voltage output but I don't believe there was negotiation on it.. the blue hand cranked dynamo off ebay
We don't know how the input circuit is constructed to deal with 5 V and 9 V. You may be right and the regulator is able to work from either of these voltages. A reasonable assumption, but not confirmed. Who knows what the electronics does when it "expects" 5 V (no negotiation) but gets 9 V? This is not a defined operating condition and anything may happen.
You don't have to. My phone is USB 2 but has this power charge option anyway (though by no means USB standard).
um yes, dinosaur days, it used to be 500ma, now the bare minimum is quick charge which relies on QC3 and delivers about 15w of power, I'm working with PD or power delivery which outputs at 20v over usb c at 3+ amps
but my phone is a bit old lol, it's about 5 years old and only supports 9v 1.5amps or 15watts or so... so instead of negotiating why not just pump 9v straight in....
I don't see why 2 switching regulators would be involved or even a good reason why a voltage regulator that can handle 9v be destroyed by expecting only 5v
Probably not 2 switching regulators.
Just a thought experiment:
The internal battery of the phone is a Lithium based one with say 3.7 V nominal voltage (give or take a few 100 mV).
The regulator expects 5 V ao it steps the input voltage down by a factor 3.7 / 5 = 0.74.
The actual input voltage is 9 V, however, supplied by your un-negotiated power supply. The regulator steps this down to ) V × 0.74 = 6.7 V.
The 3.7 V Li-battery is now charged by a 6.7 V source. This scenario calls for a rapidly swelling and exploding battery.
To operate from 9 V, the step down regulator within your phone needs to apply a factor 3.7 / 9 = 0.41 instead, but it will do so only if it is informed of the 9 V source which requires negotiation between the phone and the charger.
Of course it is entirely up to you to give it a try and make a real world experiment out of my thought experiment. I'd like to hear the outcome.
yes and me, as I don't have a backup phone I'll do it in a few months when it's time to upgrade lol
as for the regulator, I expect them to be a buck regulator and switched via and inductor capacitor combo to a lower voltage either way, my gut feeling would be it works, another option is to find the charging IC data sheet and actually see if it can or it has to be negotiated....
oh believe me if not for the fact I'm not due an upgrade I'd connect a 9v battery to it directly
bertus
Moderator
Hello,
USB-C has the capability of delivering 9 Volts or even more:
https://en.wikipedia.org/wiki/USB_hardware#USB_Power_Delivery
Bertus
USB-C has the capability of delivering 9 Volts or even more:
https://en.wikipedia.org/wiki/USB_hardware#USB_Power_Delivery
Bertus
No bets. I've said all I had to say.
bertus
Moderator
Hello,
Did you read this section:
The USB Power Delivery specification revision 2.0 (USB PD Rev. 2.0) has been released as part of the USB 3.1 suite.[58][66][67] It covers the USB-C cable and connector with a separate configuration channel, which now hosts a DC coupled low-frequency BMC-coded data channel that reduces the possibilities for RF interference.[68] Power Delivery protocols have been updated to facilitate USB-C features such as cable ID function, Alternate Mode negotiation, increased VBUS currents, and VCONN-powered accessories.
Bertus
Did you read this section:
The USB Power Delivery specification revision 2.0 (USB PD Rev. 2.0) has been released as part of the USB 3.1 suite.[58][66][67] It covers the USB-C cable and connector with a separate configuration channel, which now hosts a DC coupled low-frequency BMC-coded data channel that reduces the possibilities for RF interference.[68] Power Delivery protocols have been updated to facilitate USB-C features such as cable ID function, Alternate Mode negotiation, increased VBUS currents, and VCONN-powered accessories.
Bertus
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