Effect of MOSFET Aspect Ratio on Current Mirror Using Different Current Sources

A highly efficient current mirror circuit is the need of every analog integrated circuits. They are mainly used to bias amplifier stages in analog ICs. Current mirror circuit should provide constant, predictable and precise current. In order to do so reference current given to current mirror should be constant, predictable and precise. Objective of this paper is to discuss the various reference current generation schemes and their dependency on the Aspect Ratio of Current Mirror’s MOSFET. Current mirror circuit with Resistor based and MOSFET based reference current generation schemes is implemented in this paper and simulated for different values of Aspect Ratio of current Mirror’s MOSFET. Effect of change in Aspect Ratio of current mirror’s MOSFET on reference current value is compared for different current generation schemes to find which current generation scheme is more suitable for current mirror circuit using MOSFET.