Output Impedance Improvement of A Low Voltage Low Power Current Mirror Based on Bulk Driven Technique

This paper improved the output impedance of an LVLP current mirror by using bulk driven technique and transconductance enhancement. The applied technique increases the output impedance of current mirror significantly compared with the primary circuit. Also, it provide little improvement in input resistance and bandwidth. Operation principle of current mirror circuit with proposed improvement is discussed, the most important formulas are derived and compared with the primary circuit and its performance is verified by simulation in 0.18um technology. An output resistance of 39.5 GΩ is achieved for the improved circuit that shows 5GΩ increment in comparison with primary circuit. Besides, simulation results show an input resistance of 12.8 Ω and -3dB cut-off frequency of 216 MHz for the improved current mirror circuit while it consumes only 42.5 μW still and other specifications are still remain unchanged. Simulation is done by 1V power supply and 15μA input current.

Keywords:

Low Power Current Mirror , Bulk Driven technique , High output Impedance , CMOS