Study of variability performance of CMOS active inductors
- PDF / 1,613,434 Bytes
- 11 Pages / 595.276 x 790.866 pts Page_size
- 105 Downloads / 190 Views
(0123456789().,-volV)(0123456789().,-volV)
TECHNICAL PAPER
Study of variability performance of CMOS active inductors Vikash Kumar1
•
Aminul Islam1
Received: 4 August 2017 / Accepted: 25 December 2017 Ó Springer-Verlag GmbH Germany, part of Springer Nature 2017
Abstract The development of CMOS technology has led to the integration of communication circuits on a single chip. Inductors constitute an essential part of a RF front ends. Employment of spiral inductors has put several limitations on such RF circuits. Spiral inductors are fixed, bulky, cover large area and can’t be scaled with the process technologies. Also, due to the resistive losses and substrate losses, the quality factor is limited. An alternate way to emulate inductor behavior is using active inductors. Active inductors are area-efficient, support tunable inductance, quality factor, self-resonant frequency and can be scaled with process technologies. However, the active inductors are too sensitive to process, supply voltage and temperature variations. In this paper, four active inductor architectures i.e. basic, resistive feedback, Weng-Kuo and regulated cascode active inductor are designed. The quality factor performance of the four active inductor circuits is evaluated. Further, to demonstrate the performance of active inductors, bandpass filter configurations are implemented. The impact of process, voltage and temperature variations on the quality factor of active inductors and resonant frequency of bandpass filters is studied. Simulations are carried out at 180-nm technology node.
1 Introduction The rapid scaling of CMOS technologies have led to the development of several communication systems which need low-power, low-cost, small area and are capable of withstanding diverse communication standards all inside a single chip (Rossi et al. 2005). Nevertheless, the passive components such as inductors, resistors and capacitors are not benefited from the same Dennard scaling as transistors (Dennard et al. 1974). Inductors are the integral part for the circuits employed in radio frequency integrated circuit (RFIC) applications such as voltage-controlled oscillator (VCO), filter, low noise amplifier (LNA), phase shifter, etc (Lee 2004). Most common form of inductors used for RF applications are on-chip spiral inductors. On-chip spiral inductors however suffer from several limitations. Major limitations include low (fixed) inductance value, low-self resonant frequency, low quality factor, large die-area and process un-scalability. Moreover, there are also several losses such as metal resistance, substrate and eddy current
& Vikash Kumar [email protected] 1
Department of Electronics and Communication Engineering, Birla Institute of Technology, Mesra, Ranchi, Jharkhand, India
losses associated with the spiral inductors which restrict their use in RF applications. An alternate way is to emulate the inductor behavior using active inductors. Here, the term ‘active’ refers to realization of inductor using only active devices, i.e. transistors. A
Data Loading...
