The SW3516 and SW3518 are quite interesting DCDC step-down converters with support for PPS/ PD3/ PD2/ QC4/ QC3/ QC2/ AFC/ FCP/ SCP/ PE2/ PE1 and SFCP fast charging (+ VOOC for SW3518). They can deliver up to 20V 3A, even on the QC output, which makes it a rare "class B" capable device. The input voltage must be higher than the ouput and can range from 6-40V. You can get them on lcsc and modules on aliexpress. They often use the AON7534 30V 20A 5mOhm N Channel mosfet from A&O, so use 28V input voltage at most.
The general datasheet is available on lcsc, but register maps and schematic description are not. I found images on baidu and them into a pdf. All files are chinese only, use google translate for your phone or some other service which allows you to translate a picture.
I don't plan on designing my own circuit; I just wanted to share the information and files I had.