A Low Input Impedance Wide Bandwidth Flipped Voltage Follower Current Mirror

Abstract

Current mirror is considered as a fundamental block in the design of analog circuits. For this reason its stable high performance operation has been a key requirement by the IC engineers. A flipped voltage follower based low voltage current mirror with better stability is proposed in this paper. The proposed architecture used super cascode configuration at its output which resulted in boosted output resistance whereas the reduced input resistance is achived through super transistor configuration. Furthermore, an external capacitor is used to suppress the peaking effect observed in the frequency plot. The current mirror showed satisfactory performance with minimal error till 1 milli ampere while the power dissipated ranges in micro watts. The -3db bandwidth found to be around 2.5 giga hertz. The input and output resistances is calculated as 0.407 ohm and 103 mega ohms respectively. The robustness analysis against process and temperature variations is also presented in this paper. The proposed circuit is designed and analyzed using HSpice on 0.18 micrometer mixed-mode twill-well technology with using dual polarity supply of 0.5 volt.