The Design And Implement Of A Current Source DAC IC

This paper present a general introduction on Digital-Analog Convener study of domestic and aboard, analysis of D / A converter principle and structure, and the analysis of different converting type such as current converting and Voltage converting.Based on the study of binary weighted D / A converter and thermometer-coded D / Aconverter, a new Segmented thermometer-coded to be weighted with binary current source D/ A convener is presented according to sample rate , precision and area of circuit. The paperstudy its principle and design its cell circuits, simulate each, place them on layout as well aslay out a part of circuits.This converter has thermometer-coded to be binary weighted 2+2+2+5 architecture, the architecture implements the 11 bit D / A converter and achieve a speed of 1M /sps, INL less than 5%, DNL less than 0.5 LSB, and area is less than 0.17mm2. this D / A convener can reduce circuit area under the same rate and precision obviously.Some of the basic design theory and technology are presented within this paper. The basic cell architectures implemented in D / A converter are also presented. To improve this D / A converter, some of the cell architectures, including current source array, switch array, benchmark current, reference voltage and current, output buffer, digital control cells, have to be designed carefully. The details of these cells are described in this paper.