Patent ID: 6703956
Filing Date: 2004-03-09
Classification: H03M

Abstract:
A digital-to-analog converter for converting an N-bit binary digital input signal to an analog current signal, said N-bit binary digital input signal comprising a first group of i bits and a second group of j bits, comprising:a first binary-to-thermometer encoder which converts said first group of i bits to a thermometer code represented by 2i thermometer code bits; a first array of 2i identical current sources each of which is selectable by a respective one of said 2i thermometer code bits to contribute an identical current referenced by a first reference current to a first current signal; a second binary-to-thermometer encoder which converts said second group of j bits to a thermometer code represented by 2j thermometer code bits; a second array of 2j identical current sources each of which is selectable by a respective one of said 2j thermometer code bits to contribute an identical current referenced by said first reference current to an intermediate current signal; and a current scaling circuit which scales down said intermediate current signal by a factor of 2j to generate a second current signal; and a summing circuit which sums at least said first current signal and said second current signal to generate said analog current signal.