a low-power sixth-order gm-c low-pass filter usable in audio applications

This paper presents a gm-c tunable sixth-order active low-pass filter designed using an operational transconductance amplifier (ota) that can be utilized at the front-end of analog to digital converters (adcs) or to be used in the output of digital to analog converters (dac). the tunable filter is used to match its cutoff frequency with the bandwidth of adc and dac. the proposed tunable low-pass sixth-order filter is designed and simulated in 180 nm cmos technology at the transistor level. the simulation results show that by changing the three bias voltages in the proposed filter at the range of 0.2 v to 0.4 v, its bandwidth changes between 4 khz and 20 khz. the maximum attenuation of unwanted signals outside the bandwidth is 85 db. the power consumption of the designed filter is equal to 623 uw at the supply voltage of 1.8 v.