> >A quick question, do any of these chips provide a ring signal function?

Using a small power transformer, lets say 110Vac x 30Vac (center tap) x
300mA, two TIP30 transistors (or IRF530 FET) and 12Vdc power supply are
enough to generate around 60Vac under 20Hz, driven by a
microcontroller.   The ring generation is not a problem at all.  The
problem is to recognize the ringing phone just answered the call and the
ringing generation should stop.  One of the possibilities is measuring
the voltage over the phone line *when it is not ringing*, if it is lower
than 16Vdc then the calling phone is off hook, if it is above 16Vdc then
keep ringing.  Some extra current measurement could be done even when
ringing...

Wagner