sdk & the interwave datasheet don't seem to be clear on some things.

http://www.icst.com/ have their datasheets online but not old ones.

These guys indicate they have it(if their pdf icon can be believed), maybe(they're calling ICS, IC Sensors, I've not found an IC Sensors company).
http://www.partminer.com/servlet/FTZServlet?h … &ss=y&cs=y&ps=y#
and they'll let you have a copy from them for $10.

Plenty of sources for the actual chip but the above is about all I've come up with for the datasheet.