A comparative study of low-voltage CMOS current-mode circuits for optical communications

This paper presents a comparative study of the characteristics of low-voltage CMOS current-mode circuits for optical communications. Both the small and large-signal behavior of these circuits are examined. A new low-voltage current-current feedback CMOS current mirror and a new low-voltage pseudo-cascode CMOS current mirror are proposed. These circuits are implemented in a 0.18 μm CMOS technology and analyzed using Spectre. Simulated results demonstrate that the proposed low-voltage CMOS current mirrors offer low input impedance, large output impedance, and large bandwidth. They are particularly attractive for low-cost optical transceiver design.