Low voltage quasi floating gate current mirror with improved output impedance

Current mirror with a wide variety of application has become a basic block of analogue circuits. The main parameters affecting its performances are linearity range, input compliance voltage, input and output impedance and bandwidth. In this paper, a quasi floating gate-based current mirror design is modified in terms of increasing the output impedance. An improvement was achieved without affecting the other performance parameters of current mirror. The proposed current mirror uses the gate driven quasi floating bulk technique which results in effective transconductance as the sum of gate and scaled body transconductance. This increased transconductance boosts the output impedance from 800 kilo ohms to 3 mega ohms without degrading any of the other current mirror performance parameters. The complete analysis of the proposed current mirror is done using HSpice simulator on 0.18 um twin-well CMOS technology at a supply voltage of ±0.5 V.