in reply to: help me for design a hart modem circuit posted by kurosh.shams on 10 May 2006 at 10:46:47.
This is not an easy thing to do! For a commercial product, I recommend using one of the available chips (see www.romilly.co.uk/hmodems.htm#modemic ). Otherwise, you may find some help in Analog Services' technical library at www.analogservices.com/papers.htm .