This paper presents a high speed current mode CMOS comparator. The comparator was optimized for allows wide range input current 1mA, /spl plusmn/0.5uA resolution and has fast response. This circuit was implemented with 0.8 /spl mu/m CMOS n-well process with area of 120 /spl mu/m /spl times/ 105 /spl mu/m and operates with 3.3V (/spl plusmn/1.65V).