The ADN2820 datasheet indicates the ADN2820 is available in a butterfly package. Where can I find out more information about the specs of the photodiode?
Also, is the HMC6590 available in a package as well as die form?
The specifications of the photodiode will be depending on what vendor you will be using. Cpd, Rpd, photodiode responsivity, etc. vary from vendor to vendor.
And yes, HMC6590 is available in chips or die form like the ADN2820.
What are the specs if I bought the ADN2820 butterfly package directly from Analog Devices?
Does the HMC6590 chip form also have an in-built photodiode?