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The circuit in the link is providing 45 W output. How to increase output power to 50 W? Which component should be changed?

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    \$\begingroup\$ The reason it's designed for 45W is that's the maximum standard amount of USB power at 15 volts. There is no USB 15V 50W mode. \$\endgroup\$ Commented May 17, 2023 at 18:55
  • \$\begingroup\$ Are you asking how to get the power anyway? there's a good chance a converter designed for 45W can output 50W with no changes needed; if it triggers the over-current protection there's a good chance you can tweak a resistor to make it think it's running at 45W when it's actually 50W; of course this is all off-label use. Of course if you're using this to power a laptop or something, the laptop will still only take 45W because it knows what I just told you in the last comment. \$\endgroup\$ Commented May 17, 2023 at 18:56
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    \$\begingroup\$ The component you linked to is not capable of negotiating a higher PD profile than 15V/3A with a connected load. \$\endgroup\$
    – StarCat
    Commented May 17, 2023 at 18:56
  • \$\begingroup\$ You both are right. I just need 50 W, but it is not capable for 15 V. But I see that it can be redesigned for 20 V to get 50 W. At 20 V, it can support 45-100 W. \$\endgroup\$ Commented May 17, 2023 at 21:51

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It requires a redesign and many components would need to be changed. So there's no simple answer. At the very least it would need a new transformer, and changes to the configuration of the chip that speaks over the CC line.

And anyway: are you in the business of making USB-PD chargers? If you need one, you buy one, and that will always beat the cost of anything you can come up with yourself. So perhaps you'd need to say what exactly is the application, and why are you using that eval board to begin with.

Such eval boards are usually aimed at high-volume manufacturers, and those manufacturers usually have experienced staff on hand. So, from your question I gather that you're not working for a high volume manufacturer. Thus my point that it's very unlikely that you'd want to design such a supply yourself as a supply that works from the mains: it will not be cost-efficient to do so... But perhaps we don't know something you know, so please amend the question to clear this up.

That eval board costs more than USB-PD 50W-capable supplies, even from high-end brands (!). A 96W Apple USB-C power supply is about $60 - less than the board you look at. The best I can figure, every second you look at that eval board for purposes other than self-education is a second wasted :)

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  • \$\begingroup\$ Eval boards are targeted at anyone learning to use the chip or prototyping with one. You don't have to be in the high-volume business. However, for a USB charger I do agree you may as well go to the mall and get one from Apple or Samsung for cheaper - if one of those is good enough for you. \$\endgroup\$ Commented May 17, 2023 at 18:58
  • \$\begingroup\$ @user253751 Eval boards are targeted at anyone learning to use the chip or prototyping with one. And I agree! However, if one wants a standard wall-powered USB PD supply, there's no beating commercial high volume products. \$\endgroup\$ Commented May 17, 2023 at 19:53
  • \$\begingroup\$ I am engineering student and that is my graduation project, not doing it for my own pleasure :). My consultant asked me to design and simulate a fast charger rated at 50 W, and I have to do. \$\endgroup\$ Commented May 17, 2023 at 22:14
  • \$\begingroup\$ @FurkanAdıgüzel That's an important bit of info :) You won't be able to "modify" that board, but it can be an inspiration. \$\endgroup\$ Commented May 17, 2023 at 22:41
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You can't change it, because USB has a predefined voltage and current profiles.

As this product is limited to 3A current and to 15V, it can't advertize being capable of outputing 50W and no product would be able to request 3A.

To go above 45W accoding to PD protocol voltage would need to go up from 15V to 20V instead of current going above 3A limit.

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  • \$\begingroup\$ I saw the USB profile table, thank you for your explanation. \$\endgroup\$ Commented May 17, 2023 at 22:20

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