Hi Wesley,
Thank you for posting about the PS2303-DB9. We don’t have a data sheet for that adapter itself, but here are links to datasheets for the two main chips in it, the PL2303HX chip and RS-232 interface chip.
https://cdn-shop.adafruit.com/datashe…
https://www.exar.com/content/document…
I hope this helps.
David
Plugable Support