A D.C. stabilized analog-to-digital converter of the type having a coarse converter responsive to a supplied analog signal for converting the analog signal to a coarse digital signal representation thereof, a reconverter for reconverting the coarse digital signal representation to a coarse analog signal...http://www.google.com/patents/US4410876?utm_source=gb-gplus-sharePatent US4410876 - D.C. Stabilized analog-to-digital converter
