公开(公告)号：US5128674A

公开(公告)日：1992-07-07

申请号：US676635

申请日：1991-03-28

申请人： Kam W. Kong ,  John M. Burns ,  Tim M. Ng

发明人： Kam W. Kong ,  John M. Burns ,  Tim M. Ng

IPC分类号： H03M1/74

CPC分类号： H03M1/745

摘要： A multiplying digital-to-analog converter for multiplying a bipolar input current by a digital word A having N bits a.sub.i including a current adder for adding a constant current to the bipolar input current to produce a unipolar current, a first current mirror responsive to the unipolar current for providing N binary weighted versions of the unipolar current, a second current mirror for providing binary weighted versions of the constant current, N current selection circuits respectively controlled the N bits a.sub.i for providing an output current comprising (a) the correspondingly weighted version of said unipolar current if the associated control bit is in a first state or (b) the correspondingly weighted version of the constant current if the associated control bit is in a second state, and a shifting circuit for summing the outputs of said N current selection means and for shifting the sum current to produce a bipolar output current representative of product of (a) the input bipolar current and (b) the digital word A.

摘要翻译： 一种乘法数模转换器，用于将双极性输入电流乘以具有N位ai的数字字A，其包括用于将恒定电流加到双极性输入电流以产生单极电流的电流加法器，第一电流镜响应于 用于提供单极电流的N个二进制加权版本的单极电流，用于提供恒定电流N个电流选择电路的二进制加权版本的第二电流镜分别控制N个比特ai以提供输出电流，其包括（a）相应的加权版本 如果所述相关联的控制位处于第一状态，或（b）相关联的控制位处于第二状态的恒定电流的对应加权版本，以及用于将所述N个当前选择的输出相加的移位电路， 意味着和移动总和电流以产生代表（a）输入双极光的乘积的双极输出电流 t和（b）数字词A.