Design of a CMOS high frequency current conveyor based switched-capacitor filter with low power consumption

A new approach to the design of high-frequency microelectronic filters with low power consumption is presented. It is oriented to the realization of the circuits at the megahertz frequency range. Instead of a known transconductor based design the approach doesn´t require tuning of the filter parameters. The idea is to use current mode and voltage mode active elements with enhanced frequency range. These elements are second generation current conveyors and voltage buffers, those are used to implement integrators. The filter is realized as a switched-capacitor circuit based on an integrator chain with multi feedback loops. As an example a CMOS switched-capacitor filter with 1MHz cut-off frequency is presented. The device was realized as an unbalanced fifth-order low-pass Chebyshev filter in 0.35mum CMOS technology. The filter operates with supply voltage varying from +2.5V to +3V. Depending on the supply voltage its power consumption is from 3 mW to 10 mW, the input referred noise is 1.9 mV (0.02 + 2 MHz@ +3V), and HD3 (2V_P-to-P @ 900kHz@+3V) is -54 dB