A Novel Low Power G m-C Continuous-Time Analog Filter with Wide Tuning Range

摘要

This paper proposes a CMOS Operational Transconductance Amplifier (OTA) for wide tuning range filter applications with reduced power dissipation. The tuning range can be extended by operating the OTA in weak inversion region as well as in strong inversion region. This can be attained by tuning the bias current, which results in the linear variation of transconductance (g_m). A fifth order elliptical low pass filter is simulated with cutoff frequency tuning from 1.5 kHz to 1.6 MHz. Wide tuning range filters can be employed for multimode applications, which in-turns help in saving silicon area. A novel tunable resistor is simulated using twin well technology and its value ranges from 40 kΩ to 30 MΩ. The proposed circuit is simulated in SCL 180 nm standard CMOS technology with 1.8 V as supply voltage and achieves a dynamic range (DR) of 47 dB. Total power consumption of the circuit is 670 μW at 1.6 MHz.