Patent ID: 6617989
Filing Date: 2003-09-09
Classification: H03M

Abstract:
A device for converting an N-bit digital word to an analog voltage signal, comprising:a first circuit providing for supporting conversion of most significant bits of said N-bit digital word and comprising a switch matrix coupled to an array of resistors connected in series between reference voltages and operable to switch a voltage of said array of resistors to an output responsive to an indication of said most significant bits; a buffer having a first input coupled to said switch matrix output and a second input coupled in a feedback loop with an output of said buffer, said buffer output provides said analog voltage signal; and a second circuit for supporting conversion of least significant bits of said N-bit digital word, said second circuit comprising: an active circuit device having an input for receiving an indication of said least significant bits and an output coupled to said second input of said buffer, said active circuit device cooperable with said feedback loop for modifying said analog voltage signal by a voltage amount corresponding to said least significant bits.