The XR2206 hasn't been made for many years and is no longer available at Digikey, but some other store might still have one.
It doesn't have an input for an external triangle wave.
The ICL8038 function generator IC also hasn't been made for many years and is also no longer available at Digikey so I didn't bother looking to see if it has an input for an external triangle wave.
It doesn't have an input for an external triangle wave.
The ICL8038 function generator IC also hasn't been made for many years and is also no longer available at Digikey so I didn't bother looking to see if it has an input for an external triangle wave.