All-MOS voltage-to-current converter

A new resistorless voltage-to-current converter utilizing only MOS transistors to achieve voltage-to-current conversion with less than /spl plusmn/0.5% nonlinearity is described. The circuit uses MOS transistors in linear and saturation regions to produce an output current linearly related to the input voltage. The output current is proportional to the carrier mobility tracking the process variations. This circuit is suitable for submicron technologies where the availability of a linear resistor with moderate sheet resistance is not guaranteed. The circuit is fabricated using 0.6-/spl mu/m n-well CMOS technology, consumes less than 200 /spl mu/A, and occupies 200 mm/sup 2/ of area.