Output impedance improvement of a Low Voltage Low Power Current mirror based on body driven technique

摘要

This paper improved the output impedance of a Low Voltage Low Power (LVLP) current mirror by using body driven technique and transconductance enhancement. The applied technique increases the output impedance of current mirror significantly compared to other works. Also, it provides 0.5 Omega and 6 MHz improvement in input resistance and bandwidth, respectively. Operation principle of current mirror circuit with proposed improvement is discussed, the most important formulas are derived and the comparison between the performance of this circuit and the primary one is verified by simulation in TSMC 0.18 mu m CMOS technology. An output resistance of 39.5 G Omega is achieved for the improved circuit that shows 5 G Omega increment in comparison with primary circuit. Besides, simulation results show an input resistance of 12.8 Omega and -3 dB cut-off frequency of 216 MHz for the improved current mirror circuit while it consumes only 42.5 mu W. Also, other specifications still remain unchanged. It should be noted that in this simulation, the power supply is 1 V and the input current is 15 mu A. (C) 2016 Elsevier Ltd. All rights reserved.