1.5-V MOS translinear loops with improved dynamic range and their applications to current-mode signal processing

Novel MOS translinear loop topologies for very low-voltage applications are presented. The inclusion of dc level shifting, together with a novel biasing scheme based on two MOS transistors in the triode region, allows the operation of the loops at supply voltages as low as V_GS+2V_DSsat maintaining at the same time a large dynamic range. Several current-mode translinear circuits, both static and dynamic, i.e., geometric mean, squarer/divider, multiplier and square-root-domain filters, are implemented following this approach, demonstrating on silicon the proposed techniques.