While working with the AP33772S USB PD chip, I noticed almost ALL my USB chargers have bonus PD modes.
This laptop charger lists 5/9/15/20V, but also supports 3.3-21V programmable output—unlabeled. More below…
This $12 “emergency” charger from the supermarket checkout lists 5/9/12/15/20volt fixed output. However, the PD offers two additional adjustable output profiles: 3.3-5.9v and 3.3-11v. Another bonus!
My favorite charger from Taobao lists all the fixed voltage nodes (5/9/12/15/20) and a single adjustable 3.3-11v output. Once again, the PD offers an unlabeled option: 3.3-16v adjustable output.
A single Samsung phone charger label matches the PD profile: with two fixed (5/9v) and 2 adjustable (3.3-5.9v, 3.3-11v) outputs.
What do you think is going on? My wild guess is that the insides of the chargers evolve faster than the injection molded/silkscreened enclosure. The manufacturers update to a new chip that supports more modes, and just put it in the same shell.
That’s kind of how it works with the Bus Pirate - we order enough enclosures to last a year or two, but make actual hardware multiple times a year.