International Journal on Recent and Innovation Trends in Computing and Communication ISSN: 2321-8169 Volume: 3 Issue: 6 3853 - 3857 _______________________________________________________________________________________________ 3853 IJRITCC | June 2015, Available @ http://www.ijritcc.org _______________________________________________________________________________________ Comparative analysis of different Current mirror using 45nm technology Jaspreet Kaur 1 1 Research scholar, ECE Department, JCDM College of Engineering, Sirsa Email id- jassiarora4663@gmail.com Mr. Manish Mehta 2 2 H.O.D, ECE Department, JCDM College of Engineering, Sirsa Email id- manishmehta18@gmail.com Abstract- Current mirror is one of the most important components of integrated analog circuits design. For high performance applications, accuracy, output impedance, slew rate and settling time of current mirrors are the most important parameters. The circuit made by current mode technique uses small area, consumes less power dissipation and achieves high operation speed. . In this paper we will analyze and compare the performance parameters of different current mirrors in 45 nm technology in Tanner EDA tool. The performance parameters are power dissipation, slew rate and Transconductance. The transconductance of proposed Low Voltage current mirror is far better than the other current mirrors. Keywords— Current mirror, current mode circuits, regulated cascade, negative feedback, transconductance. __________________________________________________*****_________________________________________________ 1. INTRODUCTION Current mirror circuits are well known in the art and have found uses in a variety of applications. Generally speaking, a current mirror circuit comprises a pair of transistors where an input reference current source is connected to drive one of the transistors. The pair of transistors are connected together in a manner whereby the reference current is substantially reproduced, or mirrored, at the output of the second transistor. In most cases, the critical factor in designing a current mirror circuit is providing optimum matching between the reference and output currents Current mirrors can also be formed using MOS devices In MOS technology, small channel length devices are increasingly in demand. In relation to current mirror circuits, the decrease in channel length results in the decrease of the output impedance of the current mirror. Cascoding techniques become necessary, therefore, to increase the output impedance [1]. When the current mirror is used as a load element in amplifiers, the high incremental resistance of current mirror provides high voltage gain at very low supply voltage. The current mirror uses the principle that if the gate-source potentials of two identical MOS transistors are equal, then the current flown through their Drain terminals should be the same [15]. The common application of current mirrors are as active load, as biasing element, current amplifier, operational amplifier, analog to digital converters, digital to analog converter and current conveyor etc[3]. There are many current mirrors available; following are the performance parameters of a current mirror: 2. DIFFERENT CURRENT MIRRORS 1. Simple current mirror The basic current mirror can also be implemented using MOSFET transistors, as shown in Figure 2. Transistor M 1 is operating in the saturation or active mode, and so is M 2 . In this setup, the output current I OUT is directly related to I REF . The drain current of a MOSFET I D is a function of both the gate-source voltage and the drain-to-gate voltage of the MOSFET. In the case of transistor M 1 of the mirror, I D = I REF . Reference current I REF is a known current, and can be provided by a resistor as shown, or by a "threshold-referenced" or "self-biased" current source to ensure that it is constant, independent of voltage supply variations. Although the principle of operation for MOS transistors does not involve forward biasing of any diodes, M2 (i.e. MNMOS_1) is said to be diode connected. Assume that M1 (i.e. MNMOS_2) also operates in the active region and that both transistors have infinite output resistance. Then I D1 is controlled by V GS1 , which is equal to V GS2 by KVL. If the transistors are identical, (W/L) 2 = (W/L) 1 , And therefore I Out = I D1 = I D2 The above equation shows that the current that flows in the drain of M2 is mirrored to the drain of M1. Since βF →∞ for MOS transistors, and KCL at the drain of M2 yield I OUT = I D1 = I IN Fig 1: Simple current mirror circuit