A Low-Voltage Low-Power Resistor-Based Current Mirror and Its Applications

摘要

In this paper, a CMOS resistor-based current mirror (RBCM) aimed to be used in low-voltage applications is presented. The main features of the proposed current mirror are very low input voltage requirement (a few mV), low output voltage requirement, high output impedance and simple circuitry. The core structure of the proposed RBCM consists of three transistors (excluding bias circuitry) and two low value grounded resistors. The proposed circuit alleviates the need for cascode structures which are conventionally used to boost the output impedance and linearity. SPICE simulations using 0.18 mu m CMOS technology parameters under supply voltage of 0.9V are reported which show input and output voltage requirements of 40mV and 0.1V respectively, low THD of 1.2%, R-in of 496 Omega, R-out of 1M Omega, -3 dB bandwidth of 181MHz and power dissipation of 154 mu W. A high CMRR differential amplifier and a high performance current difference circuit as applications of the proposed RBCM are given. The proposed RBCM is very useful in tackling restrictions of modern technologies such as reduced supply voltage and transistors low intrinsic output impedance.