Thanks, Alice.
Section 47.3.7 in the document you provided describes to how to set the ADC up to gather the temperature sensor data, and the equation to convert that data into a temperature, but not the coefficients for the equation. It does state:
A, B, and α are specified constant values from the ADC electrical information in the chip data sheet
I haven't been able to find them in either of the data sheets listed on the product page:
https://www.nxp.com/docs/en/data-sheet/LPC55S3xDS.pdf
https://www.nxp.com/docs/en/data-sheet/LPC553x.pdf
(But it wouldn't be the first time I missed a needle in a haystack). Where can I find them?
Thanks